Guardant Health, based in Redwood City, California, is a leader in liquid-based cancer tests for clinical and research use. The company offers Guardant360 LDT, a liquid biopsy test for treatment selection in advanced-stage cancer, Guardant360 CDx, an FDA-approved companion diagnostic for several targeted therapies, and Guardant Omni, a broader gene panel for immuno-oncology research. In 2021, Guardant launched Reveal, a tumor-agnostic molecular residual disease test. In 2024, the company received US FDA approval for Shield, a liquid biopsy for colorectal cancer screening. Additionally, Guardant offers research development services such as regulatory approval consultancy and clinical trial referrals.