All participants were divided intothree groups: infertile women with endometritis (n=10), infertile womenwithout endometritis (n=17) and fertile women without endometritis (n=10).At hysteroscopy, two endometrial samples were obtaneid, with one sent forhistopathological examination per the gynecologist’s request and the otherused for immunohistochemistry procedures to evaluate the expression ofCD138, HOXA10 and HOXA11. CD138 wasused to confirm the diagnosis of CE. The gene discussed is HOXA11; the disease is endometritis.