HOXA4 and cancer: A previous study found that HOXB9 can mediate tumor angiogenesis, epithelial-mesenchymal transition (EMT), and cancer stemness through the TGF-β pathway, leading to chemical resistance and poor survival in pancreatic cancer patients (56); There are also studies to explore the carcinogenesis of the HOX gene cluster in head and neck squamous cell carcinoma (57) and potential tumor suppressor in renal clear cell carcinoma (20); HOXA4 and HOXA5 affect the function and prognosis of lung cancer cells and may be potential biomarkers of LUAD (58).