ACP3 and metastatic prostate carcinoma: In fact, application of an active immunotherapy regimen, Sipuleucel-T (APC8015) used by activating peripheral blood mononuclear cells (PBMCs) with a prostatic acid phosphatase (PAP), a fusion protein of prostate cancer antigen, with GM-CSF, resulted in approximately 4 month-prolonged median survival in prostate cancer patients [13]–[15], and was approved by FDA for the treatment of metastatic prostate cancers [14], [16], [17].