MCL1 and neoplasm: Unlike other strategies to deplete MCL‐1 in combination with venetoclax, our results demonstrate that 225Ac‐lintuzumab‐targeted internal alpha radiation exerts a dual mechanism of action, effecting potent single‐agent tumor killing through DNA double‐strand breaks, and the reduction in antiapoptotic proteins such as MCL‐1, leading to re‐sensitization of tumor cells to venetoclax and potent antitumor activity in preclinical models.