We recently found that ectopic endometrial MSCs expressed elevated fibrotic proteins, including collagen I, α-smooth muscle actin (α-SMA), fibronectin, and connective tissue growth factor (CTGF), compared with eutopic endometrial MSCs from women with or without endometriosis and that endometriotic peritoneal fluid promotes myofibroblast differentiation of endometrial MSCs (In Press). Here, FN1 is linked to endometriosis.