FOXP3 and Infertility: Further analysis based on the extent of EM revealed that FoxP3 mRNA expression in infertile patients with advanced EM (median, 1.20; interquartile range, 0.86-1.95) was significantly higher than the mild EM group (median, 0.38; interquartile range, 0.21-0.47) and the control group (P < 0.05).