BAX and breast cancer: BIK is an inducer of mitochondrial apoptosis by activating BAX.19, 20, 21, 22, 23 It has been reported that Star-PAP associates with BIK mRNA and thus facilitates BIK expression by processing its mRNA 3′end in HEK293 cells.9 For this reason, we speculated that the Star-PAP-induced mitochondrial apoptosis of breast cancer cells is mediated by BIK.