MCL1 and breast carcinoma: Preclinical studies demonstrated that sabutoclax (BI-97C1), an apogossypol derivative and pan-active Bcl-2 protein family antagonist (inhibiting Bcl-2, Bcl-xL, Mcl-1 and A1/Bfl-1), overcame drug resistance, eliminated cancer stem cells in breast cancer [91] and synergized with minocycline, a synthetic tetracycline, in a pancreatic cancer model [92] and with docetaxel in a model of prostate cancer [93].