NGF and varicocele: We noted positive correlations between the NGF level and the F2IsoP and IL1β levels in men with varicocele (0.80 and 0.81, respectively, p < 0.05) and men with UGIs (0.87 and 0.64, respectively, p < 0.05), and between the NGF level and sperm immaturity in all the groups (F, 0.94; V, 0.54; UGIs, 0.78; all p < 0.05).