USP4 and breast cancer: reported that the CDK1‐mediated phosphorylation of USP29 promoted the stability of Twist1 and EMT in breast cancer.[21] The E3 ubiquitin ligase FBXO3 can interact with USP4 to stabilize Twist1, thus facilitating breast cancer metastasis.[22] Notably, Twist1‐induced EMT has been implicated in promoting chemoresistance in BC.