BCL2 and renal cell carcinoma: To explore the potential mechanisms behind apoptosis-mediated resistance in renal cell carcinoma (RCC), we developed apoptosis-resistant SW839 and OS-RC-2 RCC cell lines through continuous exposure to the selective Bcl-2 inhibitor ABT-199, which is commonly used in clinical settings to induce apoptosis, particularly in chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL) 31 (Figure 1A-C).