BCL2L1 (BCL2 like 1) encodes an anti-apoptotic member of the BCL-2 family protein complex that primarily functions to inhibit programmed cell death. The protein localizes to mitochondrial membranes and regulates the intrinsic apoptotic pathway by preventing mitochondrial outer membrane permeabilization and cytochrome c release 1. BCL2L1 expression is dynamically regulated in response to cellular stress, including DNA damage and therapeutic drug treatment 2, 3. The protein's anti-apoptotic function is mediated through BH3 domain interactions with pro-apoptotic family members 4. In cancer biology, BCL2L1 upregulation represents a critical resistance mechanism in EGFR-mutated lung cancer following tyrosine kinase inhibitor treatment, with genetic ablation or pharmacological inhibition of BCL2L1/BCL-XL overcoming acquired drug resistance 1. BCL2L1 inhibition enhances apoptosis induction by multiple therapeutic agents, including daunorubicin in acute myeloid leukemia and pyrimidine synthesis inhibitors in pancreatic cancer 3, 5. Selective BCL2L1 inhibitors show senolytic activity, selectively promoting apoptosis in senescent cells with potentially reduced hematological toxicity compared to pan-BCL-2 family inhibitors 6. These findings establish BCL2L1 as a high-priority therapeutic target for combination strategies across multiple malignancies.