POU5F1 and endometriosis: Comparison of SSEA1+ sorted epithelial cells from women with endometriosis and healthy fertile control women (n = 8/group), showed a significant up-regulation of two pluripotency genes NANOG (P = 0.007) and OCT4 (P = 0.05), (Fig. 3D,E) although the abundance of OCT4 was extremely low.