ZEB1 and hepatocellular carcinoma: Another factor involved in ZEB1 degradation by the proteasome is the CRL4-DCAF15 (DDB1 and CUL4 associated factor 15) E3 ubiquitin ligase complex, which recognizes the N-terminal zinc finger domain of ZEB1 to trigger its ubiquitination and posterior degradation, reducing ZEB1 expression and the proliferative and invasive abilities of HCC cells [59].