When breast cancer cell lines MDA-MB-231, MDA-MB-436 and MDA-MB-468 were transfected with SET-targeted siRNA, CIP2A-targeted siRNA or scrambled siRNA, and then injected into the mammary gland of nonobese diabetic (NOD)/SCID/γ-chain null (NSG) mice, both SET knockdown and CIP2A knockdown reduced tumorigenic potential of breast cancer cell lines, compared with scrambled siRNA transfected cells (Janghorban et al. 2014). This evidence concerns the gene SET and breast cancer.