PSCA and prostate cancer: In addition, prostate cancer expresses numerous TAAs which include the Prostate Specific Antigen (PSA) [11, 12], Prostatic Acid Phosphatase (PAP) [13], Prostate Specific Membrane Antigen (PSMA) [12, 14], Prostate Stem Cell Antigen (PSCA) [15] and Six Transmembrane Epithelial Antigen of the Prostate (STEAP) [16].