MCL1 and lung cancer: Although genetically elevated Mcl1 levels have been reported in many tumor types [26], it has been implicated in therapeutic resistance of breast and lung cancers [450, 451], with some studies showing that Mcl1 expression can mediate resistance to Navitoclax or Venetoclax [70, 99, 452], Gemcitabine, Vincristine and Taxols [453–455].