IL-2R functionality was assessed in RCC cells cultured with or without rhIL-2 using MTT and BrdU assays to investigate cell viability and proliferation; LDH assays, Live-or-Dye staining, and Annexin V/PI staining to study cell death; and Western blot to detect apoptotic markers, cleaved PARP, and cleaved caspases 3 and 9. Here, CASP3 is linked to renal cell carcinoma.