The estradiol (E2) to testosterone (T) ratio in boys with gynecomastia, pseudogynecomastia, and healthy controls without breast enlargement (data as box plots representing 5th, 25th, 50th, 75th, and 95th percentile, P value derived from Mann-Whitney U test for individual comparisons and from Kruskal-Wallis for overall comparison). n.s., not significant.