PTEN and cancer: Candidate proteins with such anti-cancer effects include proapoptotic proteins [189]; tumor suppressor proteins, such as p59 [190], PTEN [191], and PDCD4 [192]; cytotoxic proteins, such as saporin (SAP) [193]; proteins that enhance immunogenicity, such as RNA replicase [194]; bacterial toxins, such as diphtheria toxin [195]; and inhibitors of cancer-related receptors, such as HER2 antibody [196] and PSMA antibody [197].