Using patient survival data from the clinical trial Genetic and Molecular Mechanisms in Assessing Response in Patients with Prostate Cancer Receiving Enzalutamide (NCT02099864)10, we classified patients as extreme non-responders (ENRs) (failure to achieve a 50% PSA decline 12 weeks after starting therapy and whose time on treatment was <3 months from starting therapy) vs. long-term responders (LTRs) (achieving a 50% PSA decline 12 weeks after starting therapy and whose time on treatment was >24 months from starting therapy). Here, KLK3 is linked to prostate cancer.