An increased level of erythrocyte α-synuclein with respect to healthy controls was also reported in PD patients in another study which, however, showed that higher plasma levels of α-synuclein in PD than controls had better positive predictive value and stronger correlation with disease severity than erythrocyte α-synuclein levels (Wang et al., 2019). The gene discussed is SNCA; the disease is Parkinson disease.