To elucidate the underlying mechanism by which ST6Gal-I knockdown suppresses PCa cell proliferation, migration and invasion, we analyzed the molecular expression of the PI3K/Akt/GSK-3β/β-catenin signaling pathway and related metastasis regulators in ST6Gal-I-knockdown and control PCa cells. The gene discussed is ST6GAL1; the disease is posterior cortical atrophy.