PRL and endometriosis: In this study, significantly higher concentrations of serum prolactin were observed in the endometriosis (p < 0.001) and non-endometriosis groups (p < 0.001), in comparison to the healthy women from the control group (median values: 21.88 ng/mL, 22.78 ng/mL and 12.08 ng/mL, respectively).