To gain further insight into how HIF1α induces CRC progression, we examined the effect of HIF1α on many microenvironmental genes, including TGF-β, TNF-α, VEGF, EGF, PDGF, b-FGF, HGF, and IGF, which have been implicated in promoting tumor development. This evidence concerns the gene TGFB1 and neoplasm.