TGFB1 and breast carcinoma: Interestingly, an innovative study conducted by Chaffer et al. demonstrated that non-CSCs of human basal breast cancers are a plastic cell population, with the potential to switch from a non-CSC-state to a CSC-state; this switch is regulated by the condition of the ZEB1 promoter responding to microenvironmental signals (such as TGF-β) [29].