As in AD, polymorphisms in the genes that code for GSK3β and tau (MAPT) are risk factors for PD (Kwok et al., 2005; Goris et al., 2007; Schaffer et al., 2008; Moussaud et al., 2014; Golpich et al., 2015). The gene discussed is MAPT; the disease is Parkinson disease.