A & B. MTS assay of A-498 (A) or ACHN (B) RCC cell lines treated with a combination of recombinant TRAIL (50 ng/mL A-498, 200 ng/mL ACHN) for 24 hours, IFNα (1000 IU/mL) for 72 hours, with the ERK inhibitor UO126 at the dose (μM) indicated or DMSO control for 72 hours. (A: * p=0.004, **p<0.001; B: * p<0.001, ** p<0.001 student t-test) C. A-498 cells treated with the combination of IFNα at 72 hours plus TRAIL for the last 24 hours in the presence of UO126 (5 μM) or DMSO control, stained with Annexin V/PI and analyzed by flow cytometry. D. Western blot of A-498 cells treated with or without IFNα (1,000 IU/mL) for 72 hours, serum starved for 24 hours, then treated with serum (10% FBS) for the time indicated. At the time serum was added, cells were additionally treated as indicated with or without TRAIL (50 ng/ML) in the presence of either the ERK inhibitor UO126 (5 μM) or DMSO control.