In the downstream substrates of IRS-1, phosphorylated Erk (Figure 2E and Supplementary Figure 1D) was significantly increased in the PD patients whereas no significant difference was found from the rest of substrates such as Akt and P70S6 Kinase (Figures 2C,D and Supplementary Figures 2B,C). The gene discussed is IRS1; the disease is Parkinson disease.