Furthermore, a study by Yang et al. on human hypopharingeal and lung carcinoma cell lines with HIF-1α overexpression showed that small interfering RNAs (siRNAs) can repress TWIST1, causing a shift towards the MET with the switch from mesenchymal (N) to epithelial (E) cadherin expression [56]. The gene discussed is HIF1A; the disease is lung carcinoma.