JAG2 and endometriosis: Therefore, the aim of this study was to evaluate the expression of the NOTCH receptors (NOTCH1, NOTCH2, NOTCH3), ligands (JAG1and JAG2) and target gene, and survivin, in the endometrium of patients with PCOS, endometriosis, repeated implantation failure (RIF) and healthy fertile women during the window of implantation.