SNCA and Parkinson disease: In an ELISA-supported investigation, total α-synuclein concentrations were moderately increased in saliva samples in PD patients (n = 115) compared to unaffected controls (n = 88) (PD: 285.42 ± 400.13 pg/mL; Control: 165.97 ± 272.3 pg/mL) [35].