Thanks, Alex. Good afternoon, and thank you for joining our first quarter 2023 earnings call. I will start off today's call today for providing an update on our progress so far in 2023 and go into more detail on our progress in therapy selection and MRD. I will then turn the call over to AmirAli for an update on screening. And finally, Mike will provide a more detailed look at our financials and outlook for 2023. At Guardant, we have built one of the fastest-growing platforms in diagnostics, coupled with what we believe is the most exciting pipeline in the industry to fuel long-term growth. Today, we are the market leader in therapy selection and technology innovators at the forefront of MRD in cancer screening. All of this enables us to help patients at all stages of cancer, live longer and healthier lives. In line with this, I would like to start off with a patient story. A 43-year-old woman with no history of smoking went to a physician with testing. A CT scan ruled out a pulmonary embosum but showed a 3.5 centimeter mass. Following additional tests she was diagnosed with Stage 3 lung adenocarcinoma. Further testing from other modalities indicated that tumor was negative for EGFR ALK and ROS1. However, a Guardant360 liquid biopsy revealed several somatic mutations including a ROS1 fusion, making her candidate for the targeted therapy entrectinib. Following treatment for oncologist ordered imaging to confirm whether or not she was responding to therapy, which came back inconclusive. A Guardant response test was ordered and detected no ctDNA indicating she was responding to therapy. One year into treatment she continues to do well with an over 50% reduction in the primary tumor mass and complete resolution of other nodules. Her story illustrates the power of the combined Guardant360 in Response testing regimen to assist doctors making these crucial decisions to deliver better patient outcomes. Turning to Slide 4. We started the year off strong with our first quarter revenue growing 34% to $128.7 million. Guardant360 continues to be the main growth driver with increasing contributions from Reveal and TissueNext.. Our team continues to focus on delivering superior execution, operations and customer service. All in all, we accelerated our growth in the quarter and is stable market conditions, driving market expansion and a backdrop of notable retrenchments by competitors. Turning to Slide 5. We are pleased to report that in mid-April, we received Medicare reimbursement for Guardant Response. This is our fifth assay to receive Medicare reimbursement. It is the first blood-only liquid biopsy, for immunotherapy response monitoring, representing a major step forward for patients. The overall testing program will consist of the Guardant360 test treatment initiation followed by a response test in the appropriate time frame. Our rate for response has been finalized at $1,943 and we are exploring an ADLT pathway for this test in the medium term, which should increase pricing further. Turning to Slide 6. After another record quarter, in which we continued to significantly grow market share, we want to take a moment to spotlight our core therapy selection business. Over the years, we have built on the foundation of the first FDA-approved comprehensive liquid biopsy, to create what we believe is the strongest platform in oncology diagnostics. Our entire therapy selection portfolio is now reimbursed by Medicare, with reach to over 300 million covered lives when we include commercial payers. We have established ourselves as technology and market leaders, with a greater than 300-person commercial team across clinical and biopharma, over 12,000 ordering oncologies, more than 150 biopharma customers all supported by hundreds of patents and clinical publications. Achieving scale is not a long-term vision, but at our doorstep. For therapy selection, which represents more than 95% of our total revenue, we expect to generate more than $500 million in sales this year, with clinical revenue growth of greater than 25%, gross margins above 60% and reach cash flow breakeven in six to nine months. Moving on to Slide 7. Clinical test volume reached over 39,100 tests in the first quarter, up 45% compared to the prior year quarter. Guardant360 continues to be the main driver with continued strong growth in lung cancer, with a significant uptake in breast cancer, following our CDx approval for ESR1 mutations early in the quarter. Guardant Reveal and TissueNext added to the growth, as we rapidly onboarded patients in MRD and also gained market share driven by the recent launch of our AI-powered, Guardant Galaxy tissue offering. We continue to execute on building account depth, with more oncologists ordering more Guardant test again in the quarter. This is due in large part to the leverage, we are gaining from past investments in EMR integration, processes and systems. We saw a nice upward move in our Guardant360 ASPs, supported by mix and positive momentum from commercial payers. We are closing on coverage from all major commercial payers in the US, for Guardant360 given the addition of United during Q1 Aetna, Humana expected in Q2, and others that are in advanced discussions. Our ESR1 CDx, has been a major driver and is helping us to address remaining coverage limitations. All of this is providing a tailwind for ASP. Turning to Slide 8. We had another solid quarter of biopharma growth, with volumes up 21%. Our partnerships continue to rise and we have now converted more than 20% of our mix to GuardantINFINITY, our epigenomic or smart liquid biopsy-based panel and also continue to see strong utilization of Guardant360 CDx. In addition, we announced another ESR1 collaboration and are on target to start seeing China sales ramp up later in 2023. Turning to Slide 9. With our strongest quarter yet in breast cancer, I would like to highlight the transformational potential that our CDx can have for breast cancer that develop an ESR1 mutation. Between 65% and 80% of breast cancer in women are estrogen receptor or ER positive and up to 40% of patients with ER-positive HER2 negative cases will develop an ESR mutation, which qualifies them for a new class of targeted therapy. ESR1 mutations can emerge months or years after initial tissue or liquid biopsy demonstrating a real need for liquid biopsy testing. With six biopharma partnerships focused on ESR1 already this will be a key focus area for CDx programs where our partners can leverage Guardant technical and regulatory capabilities. I'd like to take a moment to thank our team who worked tirelessly to ensure we live up to our most important value to put the patient first. Everything we do is led by that North Star. At Guardant we have built one of the most transformative platforms in diagnostics and we think extensively about how we get our work done more efficiently from development through delivery to fulfill our primary mission of helping patients. In line with that goal we recently made some key additions to our leadership team in an effort to further improve our ability to operate effectively while balancing our need to innovate quickly. Ines Dahne-Steuber joined Guardant as our new Chief Operating Officer. Ines brings more than two decades of broad diagnostics experience, including overseeing operations for labs running millions of tests per year. Under her leadership we will bring further efficiency, leverage and scale to the way we operate as a company. Darya Chudova was promoted to Chief Technology Officer. With this newly created role we are bringing together our research and development efforts for oncology and screening to leverage our products across a single platform and allow us to scale more quickly and efficiently. I look forward to their contributions and strategic leadership to help Guardant continue to scale for this next exciting chapter of our journey. I'm very proud of our team and our products and look forward to the opportunities ahead. With that, I will now turn the call over to AmirAli to provide an update on our screening business.