Good afternoon, and thank you for joining us today. Earlier today, CareDx released financial results for the quarter ended March 31, 2018. The release is currently available on the company's website at www.caredx.com. Peter Maag, Chief Executive Officer and President, and Michael Bell, Chief Financial Officer will host this afternoon's call. Before we get started, I'd like to remind everyone that management will be making statements during this call that include forward-looking statements within the meaning of federal securities laws, which are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Any statements contained in this call that are not statements of historical facts should be deemed to be forward-looking statements. All forward-looking statements, including, without limitation, our examination of historical operating trends, expectations regarding coverage decisions, pricing and enrollment matters and our future financial expectations are based upon current estimates and various assumptions. These statements involve material risks and uncertainties that could cause actual results to differ materially from those anticipated or implied by these forward-looking statements. Accordingly, you should not place undue reliance on these statements. For a list and descriptions of the risks and uncertainties associated with our business, please see our filings with the Securities and Exchange Commission. CareDx disclaims any intention or obligation, except as required by law, to update or revise any financial projections or forward-looking statements, whether because of new information, future events or otherwise. This conference call contains sensitive information and is accurate only as of the live broadcast today, May 10, 2018. This call will also include a discussion of a financial measure that is not calculated in accordance with Generally Accepted Accounting Principles. Reconciliation to the most directly comparable GAAP financial measure may be found in today's earnings release filed with the SEC. I will now turn the call over to Peter. Peter Maag Thanks, David, and good afternoon, everyone. Thank you for joining us. We had an exciting first quarter. Most importantly, we gained significant traction on our transplantation focused initiatives. We recently welcomed the National Kidney Foundation's CEO, Kevin Longino, to our headquarters at CareDx. We have tremendous respect for what Kevin and his team at the National Kidney Foundation are doing, and would like to give a shout out to them at the start of this call. This afternoon, I will provide an update on the recent achievement across our three key business drivers: AlloSure, AlloMap and pre-transplant. I will also provide commentary on our recent agreement with Illumina, which we see as tremendous external validation from the technology leader in the industry of our strategy to build CareDx into the partner of choice in transplant care with respect to inflammation [ph]. It also marks another highlight for CareDx in a stream of positive news since the beginning of this year. After my update, Mike will provide additional financial details on our first quarter performance and discuss our 2018 guidance. It's great to see the acceleration of our top line with total revenues growing 21% year-over-year to $14.1 million, driven by a 34% year-over-year increase in testing revenue to $10.6 million. Now firstly AlloSure. We are delighted that in a short time since launch, AlloSure has made a big impact at many transplant centers as well as across the wider transplant community. Our approach to better kidney transplant surveillance is being embraced by patients and transplant centers. At the end of the first quarter, 52 centers have provided AlloSure results to their transplantation since launch, which is more than our initial internal projections. CareDx provided 1,051 patient results in the first quarter to 842 kidney transplantations. We continue to see gross demand for AlloSure, both with patients who recently received a kidney transplant as well as patients that received their kidney allograft in previous years. We remain focused on driving adherence to the AlloSure routine testing schedule and have seen multiple centers utilizing the recommended testing protocol. In the first quarter of 2018, 568 new standing order patients were added to the 115 standing order patients from the previous quarter. We defined standing order patients as patients that will follow the surveillance protocol for at least one-year. Tracking standing order patients is important as it represents the basis of our flywheel dynamic, which we use to describe the recurring revenue effect from patients adhering to our hearts protocol. An important element to establish this protocol is the rollout of our clinical trial, also known as our Kidney Outcome AlloSure Registry or K-OAR. As a reminder, K-OAR is out of our Medicare coverage with data development commitment. K-OAR follows patients longitudinally for three years. The study will enroll 1,000 patients across 35 transplant centers with the primary endpoint centered on observing patient outcomes at one, two and three years post transplantation. In addition to providing a wealth of clinical data, we estimate K-OAR will generate more than 10,000 AlloSure testing opportunities over the next five years, representing incremental AlloSure volume. As of end of March, 2018, 12 centers have been initiated as K-OAR study sites and 63 patients have been enrolled, which is in line with our internal expectations. The team continues to execute well on all of our studies. We see the in-house capability of running multicenter studies like K-OAR as a strategic advantage for the company. Studies provide us with an additional touch point with large transplant centers and keep us in direct dialogue with the key innovation hub and opinion leaders. We also view world class institutions participating in K-OAR as a validation of the potential of this innovative technology. It also fits well with our theme of being the partner in transplant care, as these clinical research collaborations provide a great platform for scientific exchange. For example, we set ourselves the goal to support 10 or more investigator initiated clinical trials by year-end. These trials provide learning opportunity and supports the generation of important clinical data for the field of transplantation. We are currently preparing for the American Transplant Congress meeting in Seattle, in June, which is clearly a highlight this year. The company will showcase AlloSure's capability at a large symposium entitled Innovation in Allograft Health Surveillance, clinical implementation of AlloSure testing for kidney transplant patient. The symposium will include seven renowned physicians in kidney transplantation sharing their clinical experience with AlloSure. We are excited about the number of case studies that will demonstrate the utility of AlloSure. Following the symposium, CareDx will be hosting a press conference to highlight new AlloSure data, and Dr. Daniel Brennan, the Medical Director of the Comprehensive Transplant Center at John Hopkins Hospital, will be available for a question-and-answer session. Now shifting to AlloMap. First quarter 2018 test volume increased 3% year-over-year translating into 3,847 patient results. We would like to remind everyone of the inclement weather that impacted several territories in the US during the first quarter of 2018. We believe that the various weather issues in the Southeast Central and Eastern US had a noticeable impact on volumes during the quarter. Notwithstanding this, the first quarter volume growth was still within our overall volume growth target range, and we remain focused on our strategy to broaden patient adherence. With HeartCare, we are excited about building out our offering in heart transplant surveillance. The receptivity of the heart transplant community has been fantastic. HeartCare is a comprehensive solution for rejection surveillance, as it combines our legacy gene expression based AlloMap test with our donor derived cell free DNA based AlloSure heart test. This provides heart transplantations with information on top, their immune system activity as well as graft out. HeartCare has recently launched at ISHLT, the International Society for Heart and Lung Transplantation. But it was great to hear that CareDx is viewed as a disrupter in the field of transplantation care, as we are starting to integrate multimodality testing under our common offering, HeartCare. With so much tailwind, we have increased our field and service team territories from seven to 10, which enables us to improve our coverage in major metropolitan areas, like New York, LA and Chicago. We now have dedicated CareDx transplant account managers, medical science liaisons, clinical research associates, patient care managers and draw site coordinators across the US who provide an unique service offering to transplant centers. Now turning to pre-transplant. Our pre-transplant revenues decreased 10% in the quarter to $3.3 million, reflecting a decline in our legacy Olerup SSP and SBT product and the delay last year of our Olerup QTYPE development efforts. In April 2018, we announced that Olerup QTYPE has received CE Mark approval and is now available on both Roche and Applied Biosystems platforms. We're now scaling up manufacturing to meet the market demand from US and European customers. As a reminder, QTYPE is a significant improvement in HLA type offering speed and precision for samples that require a fast turnaround time. Olerup QTYPE represents an important growth driver for CareDx, and its recent CE Mark and availability on multiple platforms should help accelerate the company's path to profitability. This week, we announced that Illumina has chosen CareDx as the exclusive partner for its existing next-generation sequencing HLA transplantation business. This strategic licensing and commercialization agreement is another step for us in creating a global leader in data driven transplantation solution. As a result of the agreement, CareDx will be the sole distributor of Illumina's TruSight HLA solutions. These products lead the market in the rapidly growing next generation sequencing HLA typing segment and are currently sold globally. While Illumina will continue to sell their generic NGS products to competitors in the HLA deal, CareDx will have the exclusive rights to finalize the development and commercialization of Illumina's new transplant focused NGS products. Illumina had made significant progress on developing these clinical applications for NGS technology and CareDx takes them over at an exciting phase, as they are transferred into clinical practice. CareDx will be branding these NGS product under the umbrella of AlloSeq. I will now talk you through these various products. AlloSeq HLA, AlloSeq BMT and AlloSeq Cell-free DNA. Firstly, AlloSeq HLA will significantly improve existing NGS HLA product offerings, by enhancing turnaround time and workflow to make this a best-in-class NGS HLA typing product. The product will be an advancement to the hybrid capture technology that Illumina has been developing for various applications. CareDx will finalize the development of the technology for the field of transplantation and we will add proprietary software to the offering. We anticipate AlloSeq HLA will be launched in the first half of 2019. With AlloSeq BMT, bone marrow transplant, CareDx will develop a next-generation sequencing solution to enter the bone marrow transplant market. This product will evaluate the level of donor versus recipient cells in post-transplant blood or bone marrow specimens in patients who have undergone allogeneic hematopoietic stem cell transplantation. Strategically, this is important as it allows us to expand from our focus on solid organ transplantation into a changing field. AlloSeq BMT will be made available in the beginning of 2019. Finally, with this agreement, CareDx get the head start on developing a kitted cell-free DNA solution. This will be important as we evaluate making cell-free DNA testing available in countries in which the diagnostics market is dominated by in-vitro diagnostic offerings. AlloSeq Cell-free DNA has been developed by Illumina to an alpha version. CareDx plans to advance the development and anticipates to commercialize this as a kitted cell-free DNA testing solution. As we are already serving a large percentage of transplant labs today with our Olerup product line, we potentially see AlloSeq Cell-free DNA as an option to support better patient care in a distributed model. As we would like to evaluate customer expectations for this offering, we have not finalized our launch assumptions for AlloSeq Cell-free DNA. Based on our financial projections, the new business generated from the Illumina agreement will add to our top line in 2018. We will see distributor like gross margins of 20% to 30% on the existing TruSight business and an OpEx increase of roughly $2 million to $3 million. Therefore, we do not anticipate the agreement to significantly impact our goal of achieving non-GAAP EBITDA profitability in the second half of this year. These new development and commercial activities will lead us to increase our planned headcount by approximately 10 to 15 in 2018. Specifically, we plan to fortify our pre-transplantation team by adding several experts in the field of next-generation sequencing testing's. I'm very pleased that David Sayer, a renowned expert in this field, has chosen to join CareDx. David has recently been with Illumina. He came to Illumina with the acquisition of Conexio, where David was the President and CEO. He and his team have significantly advanced HLA testing technologies for decades. This strengthens CareDx considerably, and we are very pleased to welcome David and his team to CareDx. We are continuously delivering on our promise to bring next-generation sequencing solutions to the transplant clinic. And with these additions to our product portfolio, CareDx is uniquely positioned to provide genomic information to transplantation. This will further enable personalized medicine in this high need, high cost patient population. Turning now to the financials. We recently announced the completion of our efforts to simplify our balance sheet by refinancing our remaining debt with a single term loan with Perceptive Advisors. Mike and the team have done a great job in heading the company up for growth and providing us with the financial backbone and flexibility to support our growth. Mike, I'll hand the call over to you to discuss financials.