Furthermore, 1,25D suppressed the expression levels of claudin1, p-AKT and pluripotency markers by inhibiting β-catenin, and by forcing claudin1 expression and activating AKT, we further determined that 1,25(OH)2D3 may reduce cancer cell stemness and suppress gefitinib resistance by inhibiting claudin1/AKT pathway. The gene discussed is CLDN7; the disease is cancer.