However, a 2020 study by Reinehr pointed out that prolactin concentrations were consistently within the normal range in both boys with gynecomastia (median 9.3 [IQR 7.0–16.2] ng/mL) and boys with pseudogynecomastia (median 10.3 [IQR 8.0–14.3] ng/mL), with no significant difference between the two groups [21]. The gene discussed is PRL; the disease is Gynecomastia.