SIRT1 and breast cancer: Additionally, the stability of the oncogenic transcription factor FOXM1 is regulated by O‐GlcNAcylation: under normal conditions, FOXM1 undergoes SIRT1‐mediated ubiquitination and degradation, whereas high levels of O‐GlcNAcylation in breast cancer inhibit the AMPK–SIRT1 axis, enhancing FOXM1 stability and exacerbating malignant behavior [266, 267].