CNTNAP4 and Parkinson disease: Here, for the first time, we detected CSF and plasma CNTNAP4 concentrations in human PD patients and found that CNTNAP4 expression in both was increased in PD patients (CSF, controls: 29.22 ± 4.39 ng/mL and PD patients: 33.98 ± 3.72 ng/mL; t = 4.779, df = 77, P < 0.0001; Figure 11E; plasma, controls: 103.20 ± 8.52 pg/mL and PD patients: 163.50 ± 20.30 pg/mL; t = 2.737, df = 178, P = 0.0068; Figure 11F).