Moreover, Ding and colleagues have reported that silencing of HIF-1α represses cell invasion and induces apoptosis by downregulating the expression of WW domain containing E3 ubiquitin protein ligase (WWP9, WWP2), VEGF, and VEGFR2 in thyroid cancer (44) as depicted in Figure 2. The gene discussed is HIF1A; the disease is thyroid gland carcinoma.