In the hypoxic regions of breast cancer, cervical cancer, gastric cancer, and other tumor cells, the abnormal expression of E-cadherin can lead to the abnormal regulation of the related signaling pathway, which will affect the adhesion, invasion, metastasis, and survival of cells, and the abnormal expression of E-cadherin is often closely related to the overexpression of HIF-1α in the hypoxic environment of tumors (17, 18). The gene discussed is CDH1; the disease is breast cancer.