PRF1 and posterior cortical atrophy: Flow cytometry results using localized PCa samples without ADT showed that upon stimulation, CD8+CXCR6+ lymphocytes secreted more GZMB and PRF1 compared to CD8+CXCR6− lymphocytes (Figure 4M,N), indicating that CD8+CXCR6+ lymphocytes can mediate target‐cell death by cytotoxic granule proteins.