Because the CTS of Bim also functions to activate the pro-apoptotic proteins Bax and Bak, (Chi et al., 2019) our results suggest that BH3-mimetics may have unpredictable results in cells depending on the Bcl-2 family proteins expressed and that targeting both binding sites on Bcl-XL and/or Bcl-2 may be required to kill some cancer cells that have bypassed apoptosis by inhibiting Bim. Here, BCL2 is linked to cancer.