Previous studies confirmed that extracellular vesicles and/or extracellular vesicles-derived microRNA-126-5p (44) and proteins could regulate the proliferation, migration of endometrial mesenchymal stem cells by negatively regulating the expression of BCAR3 (a kind of EMT-associated genes), as well as enhance the angiogenic abilities, subsequently affect the occurrence and metastasis of endometriosis. The gene discussed is BCAR3; the disease is endometriosis.