HIF1A and cancer: Recent studies indicate that STC1 expression is involved in the formation of tumor vasculature through up-regulation of vascular endothelial growth factor (VEGF) [13,14], STC1 can induce adaptive responses to hypoxia in human cancer cells through the regulation of hypoxia inducible factor-1-alpha (HIF-1α), a process that is closely associated with carcinogenesis and the progression of RCC [30,31].