These ongoing studies will allow us to elucidate the potential for context-dependent differences in Bcl-2 family inhibitor–mediated radiosensitization across a more heterogenous population of breast cancer models and would build on recent literature demonstrating differences in sensitivity to Bcl-2 family inhibitors across different breast cancer subtypes (20, 32, 42, 43). This evidence concerns the gene BCL2 and breast cancer.