Mirabi et al. (2019) reported in their retrospective cohort study, which included 114 infertile women with endometriosis and 101 infertile women without endometriosis, that the prolactin serum levels were higher in infertile patients with endometriosis compared to infertile patients without endometriosis: 23.42 ± 34.05 ng/mL in the infertile women with endometriosis stages I and II; 31.62 ± 38.09 ng/mL in the infertile women with endometriosis stages III and IV; and 17.88 ± 12.81 ng/mL in the group of infertile women without endometriosis. This evidence concerns the gene PRL and endometriosis.