PRL and endometriosis: A statistically significant relationship was found between the basal serum PRL level and the stage of endometriosis (16.98±1.29 ng/mL for stages I; 18.07±1.50 ng/mL for stages II; 25.59±1.96 ng/ mL for high stages III-IV) compared to healthy controls (17.21±1.22 ng/mL) (p=0.01).