Similarly, the authors of a recent meta-analysis comparing the diagnostic accuracy of different hormonal biomarkers for diagnosing endometriosis reported low sensitivity (0.45) but high specificity (0.92) for serum prolactin when compared with other hormonal markers such as aromatase, human chorionic gonadotropin/luteinising hormone receptor, oestrogen receptor (ER)-α, ER-β, oestrogen sulfotransferase, and 17β-hydroxysteroid dehydrogenase type 2. This evidence concerns the gene PRL and endometriosis.