CDKN2A and posterior cortical atrophy: Interestingly, in contrast to the degradation of p16, UBE2S knockdown markedly reduced the expression of β-catenin but was not attenuated after treatment with MG132 for 12 h, suggesting that UBE2S stabilizes β-catenin during nonubiquitination degradation in PCa cells (Fig. 4B).