As shown in Fig. 1c, the relative CHCHD2 protein levels were decreased significantly from 1.01 ± 0.07 in pooled erythrocytes of controls to 0.43 ± 0.12 in those of PD patients (p < 0.05, Mann–Whitney U test, n = 3). The gene discussed is CHCHD2; the disease is Parkinson disease.