In contrast to earlier studies with ccRCC cell lines and tumor xenograft studies which suggested the role of HIF1α as a tumorsuppressor, more recent mouse transgenic model with constitutive activation of HIF1α demonstrated the role of HIF1α in the early ccRCC lesion formation, such as renal cyst and clear cell morphology. The gene discussed is HIF1A; the disease is nonpapillary renal cell carcinoma.