Table 1.

Mechanisms of resistance to sunitinib and everolimus

Potential mechanisms of sunitinib resistance

Hypoxia resistance of RCC cells

Vascular resistance to VEGFR and PDGFR inhibition by sunitinib

Potential mechanisms of everolimus resistance

Resistance of RCC cells to direct anti-proliferative everolimus effects

Resistance of HIF1α target gene expression to repression by everolimus

Hypoxia resistance of RCC cells

Vascular resistance to VEGF pathway inhibition

PDGFR, platelet derived growth factor receptor; RCC, renal cell carcinoma; VEGF, vascular endothelial growth factor; VEGFR, VEGF receptor.