Notably, KEAP1 is reported to be O-GlcNAcylated, which elevates KEAP1 E3 ligase activity and promotes the degradation of NRF2 in cells with increased cellular O-GlcNAcylation [94], suggesting that NRF2 is not involved in the activation of proteasome subunit genes in cancer cells with high O-GlcNAcylation activity. Here, NFE2L2 is linked to cancer.