Anti-CD38 monoclonal antibodies are shown to be highly efficacious in the treatment of multiple myeloma (MM) and pre-clinical studies highlight the potential use in other tumors such as CLL, lung cancer, prostate cancer and melanoma (29, 70, 72–74, 76, 95–99) and in a preclinical model of melanoma (87). Here, CD38 is linked to prostate cancer.