IL15 and cancer: Efficacy was observed with IL-15 in multiple murine immunotherapy trials including the syngeneic TRAMP (transgene adenocarcinoma mouse prostate) -C2 prostatic cancer, Pme1-1, B16 melanoma, MC38 and CT26 colon carcinoma models suggesting that IL-15 might be more effective than IL-2 in cancer therapy (38–40).