HIF1A and hereditary clear cell renal cell carcinoma: However, HIF-1α and HIF-2α have differed distribution of binding with respect to the transcriptional sites at promoters with HIF-1α binding more frequently close to (within 5 kb) and HIF-2α binding more frequently distant (>5 kb) from transcriptional start sites in HKC-8 cells, renal cell carcinoma RCC4 cells, and hepatoma HepG2 cells [43].