To characterize B7-H3 expression in same-patient, castration-sensitive PC (CSPC) and castration-resistant PC (CRPC) biopsies, associating this with PC genomics, and to evaluate the antitumour activity of an anti-B7-H3 antibody-drug conjugate (ADC) in human CRPC in vitro and in vivo. This evidence concerns the gene CD276 and pachyonychia congenita.