CDKN2A and Huntington disease: As depicted in Figure 1, there was a significant negative correlation between Nrf2 and CDKN2A expression levels in whole blood of 34 HD patients (rho=-0.51, P=0.002); while no significant correlation was found between Nrf2 expression level and chronological age (rho=-0.02, P=0.91; Figure 2).