GNRH1 and keratoconus: GnRH saliva concentrations were lower in both male and female KC subjects (76.7 pg/mL, IQR 29.1–151.7 pg/mL and 80.7 pg/mL, IQR 38.2–179.2 pg/mL, respectively) compared to sex-matched control patients (121.1 pg/mL, IQR 61.0–190.4 pg/mL and 116.9 pg/mL, IQR 70.9–179.2 pg/mL, respectively), though this effect was only significant in the males (p = 0.0222, Figure 2B).