CD44 and endometriosis: Paired eutopic (E-Eutopic) and ectopic endometrial MSCs (passage 5) derived from patients with endometriosis and eutopic (C-Eutopic) endometrial MSCs (passage 5) derived from patients without endometriosis were identified for the expression of positive MSC markers CD44, CD73, CD90 and CD105, and negative MSC markers CD34 and CD45.