No differences were found between the morning and the evening protein concentrations in the case of BDNF (p = 0.162) and proBDNF (p = 0.791) in all participants of the study; similarly, no differences were observed in the control group (p = 0.232 and p = 0.439 respectively) and the OSA group (p = 0.624 and p = 0.821 respectively) (Figure 1). The gene discussed is BDNF; the disease is obstructive sleep apnea syndrome.