The effects of treatment on α(II) PH, endostatin, and arresten levels in RCC xenografts. A, B). The expression of all three proteins was induced by sunitinib treatment and levels did not diminish with the onset of drug resistance. C, D). Levels of endostatin and arresten were increased by treatment with either sunitinib or MI-319 but the inductive effects of the two drugs were not additive. Lanes represent data from individual tumors for each treatment group.