FORTUNE — Flatiron Health, an oncology platform founded by two ad-tech veterans, is nearing a close on at least $100 million in new funding, according to sources familiar with the situation. Google Ventures is leading the round, the sources said. Fortune was unable to confirm if other investors, including existing ones, participated in the round.
Flatiron Health and Google Ventures did not respond to requests for comment.
Flatiron Health builds data pipelines, infrastructure, and software for the cancer industry. The small idea is that pooling data will lead to better decision-making around diagnosis and treatment. The big idea is that big data could eventually cure cancer. The company’s product, OncologyCloud, is in beta with 25 cancer center partners serving 100,000 patients, according to its website.
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Zach Weinberg and Nat Turner founded Flatiron Health in 2012 after leaving Google (GOOG). They’d sold their ad-tech company, Invite Media, to Google in 2010 for $81 million.
Google Ventures is no stranger to health care startups. The firm has backed 23andMe, One medical Group, Doctor On Demand, Transcriptic, and Predilytics. Foundation Medicine, a company that brings genomic analysis to cancer treatment, went public last Fall.
Prior to this funding, Flatiron Health raised $8 million in Series A venture funding from Google Ventures, First Round Capital, Social+Capital Partnership, Laboratory Corporation of America, IA Ventures, SV Angel, Great Oaks Venture Capital, and BoxGroup. The company lists 25 employees on its website.