The issue provides a biologic background for the increasing use of PSMA in diagnostics and therapy for patients with prostate cancer.The issue aims to include original preclinical and clinical research studies, multicenter studies and new single institution experience, and insights in the tumor biology of PSMA (FOLH1). The issue especially welcomes studies that elucidates clinical heterogeneity of PSMA expression in prostate cancer, epigenetic regulation and analysis of the impact on the epigenetic regulation from the microenvironment in major sites for the dissemination of prostate cancer in patients. The issue also welcomes studies of the impact of androgens on PSMA expression in prostate cancer. Also other innovative and comparative studies are welcome.