These findings demonstrated that persistent activation of EZH2 is required for promoting tumorigenesis and maintenance of basal-like phenotype of the cancer cells and that expression of constitutively active EZH2 (EZH2T416D) not only promotes tumorigenesis but also reprograms the committed luminal breast cancer cells into the basal-like subtype. This evidence concerns the gene EZH2 and breast carcinoma.