TGF-β1 has been shown to reduce the cytotoxicity of natural killer cells by downregulating the expression of NK Group 2, Member D in women with endometriosis [21], and was found to increase the expression of vascular endothelial growth factor-A through the inhibitor of DNA binding 1 pathway in women with endometriosis [22]. The gene discussed is TGFB1; the disease is endometriosis.