Armstrong and collaborators in the prospective multicentric study (The PROPHECY Study) showed that AR-V7 detected in the blood of mCRPC was associated with shorter PFS and OS after abiraterone or enzalutamide treatment [153] On the other hand, in circulating tumor cells (CTCs) from AR-V7-positive PC, taxanes are more effective, while in AR-V7-negative PC, the effect is comparable [154]. Here, AR is linked to pachyonychia congenita.