A positive immunoreactivity of claudin-10 could also be identified in nearly all the endometriotic epithelial cells as well as in nearly all the endometriotic lesions of the three endometriotic entities: ovarian (Figure 3A), peritoneal (Figure 3B), and deep-infiltrating endometriosis (Figure 3C). The gene discussed is CLDN10; the disease is endometriosis.