PIAS1 and posterior cortical atrophy: Apoptosis markers (Supplemental Figure 6G), flow cytometry (Figure 6D), and TUNEL staining (Figure 6E and Supplemental Figure 6H) indicated that PC-3 cells carrying PIAS1-S468A were more sensitive to olaparib-induced apoptosis, whereas those carrying PIAS1-S468D were resistant to olaparib (Figure 6, D and E, and Supplemental Figure 6, G and H), further suggesting the importance of CK2-mediated phosphorylation of PIAS1 in DDR and the response of PCa cells to olaparib.