Proliferation of tumor and tumor-associated cells is stimulated by HIF-1 through the induction of genes encoding insulin-like growth factor (IGF) 2 as well as IGF binding proteins 1, 2, and 3; TGF-α and TGF-β3; and VEGF [296, 297] (Fig. 5). This evidence concerns the gene IGFBP1 and neoplasm.