At Natera, CEO Steve Chapman is working with the smallest warning signs cancer leaves behind. Signatera, the company’s personalized blood test for cancer recurrence, looks for tiny traces of tumor DNA after treatment. In some cases, it can detect recurrence up to two years before a tumor’s return shows up on a scan. “Cancer doesn’t get a head start because we see it coming,” he said at the company’s 10-year public-market anniversary.

To build each test, Natera sequences a patient’s tumor and healthy DNA, finds the genetic signature unique to that cancer, then hunts for its traces in a blood draw. Chapman has said that “about 20 to 50% of patients will have disease recurrence in their lifetime,” and Signatera is designed to flag it early enough to act. Nearly half of U.S. oncologists now use it. The company has run more than 17 million tests, become cash flow positive, and reached a market capitalization of more than $39 billion as of August 5, 2026.

Chapman is a scientist by training who became one of the field’s foremost authorities on turning genetic tests into everyday clinical practice. He started as a researcher in human genetics at UCLA, designing arrays to find variants tied to multiple sclerosis, then spent time at Genzyme Genetics before joining Natera, where he rose through operating roles to chief operating officer and, in 2019, CEO.

Under him, the company has launched 20 products, among them two of the fastest-growing genetic tests ever, spanning oncology, organ transplant health with Prospera, chronic kidney disease with Renasight, and prenatal care with Panorama.

Chapman is continuing to push Signatera beyond its original capabilities. Natera’s December 2025 acquisition of Foresight Diagnostics brought ultrasensitive phased-variant technology into the test and opened a path into lymphoma. In May, Signatera became the first blood-based molecular residual disease companion diagnostic approved by the FDA, allowing doctors to use its results when deciding whether certain bladder cancer patients could benefit from immunotherapy.

The following month, Signatera became the first ctDNA-based residual disease test to receive a Category 1 recommendation from the National Comprehensive Cancer Network for muscle-invasive bladder cancer. Then, in July, a study in JAMA Dermatology found that Signatera detected 90% of Merkel cell carcinoma recurrences, compared with 55% for the standard antibody test—and caught them months sooner.

Chapman says Natera will “keep rewriting what’s possible, one patient and one sample at a time.” If he has his way, the warning signs will only get harder to miss.