Currently, there are several clinical trials using immunotherapy against prostate cancer targeting prostate cancer-associated antigens including Prostate-Specific Antigen (PSA) [152], Six-Transmembrane Epithelial Antigen of the Prostate (STEAP) [153], Prostate Stem Cell Antigen (PSCA) [154], Prostate-Specific Membrane Antigen (PSMA) [54, 155], and Prostatic Acid Phosphatase (PAP) [156]. Here, STEAP1 is linked to Familial prostate cancer.