KLK3 and Familial prostate cancer: Specifically, in subgroups with features that portend unfavorable prostate cancer outcomes—age <65 years, pT3 stage, PSA > 10 ng/mL at diagnosis, and Gleason Grade 9—there was a significantly higher risk of clinical failure if these patients had a high density of PD-1 positive intratumoral lymphocytes [63].