Baseline BDNF levels were significantly higher in the s-OSA group compared to the ns-OSA group (20.1 ng/mL vs. 8.1 ng/mL, p = 0.02) and correlated with the apnea–hypopnea index (AHI, r = 0.38, p = 0.02). The gene discussed is BDNF; the disease is obstructive sleep apnea syndrome.