STEAP1 is expressed in ~90% of prostate cancers and in subgroups of other cancers, such as Ewing sarcoma, lung cancer, bladder cancer, breast cancer, pancreatic cancer, glioblastoma, ovarian cancer, leukemia, lymphoma, and head and neck cancer [23,24,25,26]. This evidence concerns the gene STEAP1 and Familial prostate cancer.