Personalis is a cancer genomics testing company focused on liquid biopsy-based Minimal Residual Disease (MRD) testing — detecting circulating tumor DNA (ctDNA) in blood to monitor cancer recurrence and treatment response. Its core product, NeXT Personal, sequences a patient's tumor and normal tissue to build a personalized detection assay, then uses that assay to analyze blood samples over time. Personalis claims NeXT Personal can detect as little as one tumor DNA fragment per million DNA fragments in blood, which the company argues gives it a sensitivity advantage over competing tests. Personalis sells to two main customer groups: pharma and biopharma companies, which use NeXT Personal to run clinical trials and ImmunoID NeXT for tumor profiling and biomarker research; and physicians and cancer patients, who use NeXT Personal Dx for post-treatment surveillance. Moderna is a notable biopharma customer. On the clinical side, Personalis partners with Tempus — a larger cancer diagnostics company — as its primary commercial engine, given Personalis' own sales force is small. Personalis also performs whole genome sequencing for population-level programs like the VA Million Veteran Program. Personalis charges per test completed. The biopharma business is project-based and lumpy; the clinical business is currently near-zero revenue, as Medicare reimbursement is only beginning to come online. Personalis recently received Medicare coverage for breast cancer and non-small cell lung cancer, and management views broader reimbursement as the key inflection point for clinical revenue growth.