The development of a biomarker to identify people with prostate cancer increased the diagnosis of the disease, but did little to suggest the appropriate course of treatment for individual patients. Kenneth Pienta, professor of urology and co-director of the Johns Hopkins University InHealth Signature Initiative, is trying to change that by using surveillance and extensive data gathering to continuously stratify patients and refine treatment approaches. Pienta, who will be speaking at the Precision Medicine World Conference in Mountain View, California January 22 to 24, discussed InHealth, how its transforming the treatment of prostate cancer patients, and why it may be a model for applying precision medicine approaches to a broad range of diseases.