HIF1A and hereditary clear cell renal cell carcinoma: For example, in von Hippel-Lindau-defective renal cell carcinoma (RCC), HIF-1α inhibits cell proliferation in vivo or in vitro, and the knockdown of HIF-1α promotes tumor growth accordingly [32], while EPAS1 is shown to be essential for the growth of xenograft in RCC [11].