BAX and breast cancer: In line with these studies, which demonstrate that genetic manipulation of MCL1 alters tumor development, pharmaceutical targeting of MCL-1 with the BH3-mimetic S63845 can also inhibit growth of established MMTV-PyMT tumors in a BAX/BAK-dependent manner, indicating on-target efficacy of pharmacological inhibition of the canonical MCL-1 function to inhibit mammary tumor growth [118].