MKI67 and posterior cortical atrophy: Cellular experiments involving A3C expression manipulation (overexpression or knockdown) in multiple PCa cell lines, combined with CCK8, Ki67 fluorescence staining, wound healing, and Transwell assays, demonstrated that A3C overexpression inhibited cell proliferation, migration, and invasion, while A3C knockdown partially promoted these malignant phenotypes—confirming A3C’s tumor-suppressive role.