In our breast cancer TMA analysis of Apt63 binding, including biopsies representing 416 subjects, surface ATP5B appears to define a unique subset of highly aggressive breast and prostate cancers, present on 45% of DCIS and 55% of invasive ductal carcinomas, and on almost all (91.3%) lymph node metastases. Here, ATP5F1B is linked to Familial prostate cancer.