PDCD1 and prostate carcinoma: PD-1/PD-L1 signaling axis has been demonstrated to play a role in regulating tumor microenvironment of prostate cancer, and Gevensleben et al. found that 52.2% of 209 primary prostate cancer samples expressed moderate to high PD-L1 levels and PD-L1 positivity was prognostic for biochemical recurrence [60].