Although some eQTLs have been nominated for brain diseases, such as MAPT in Parkinson's disease (PD) and progressive supranuclear palsy (PSP) (Hoglinger et al., 2011, Nalls et al., 2011b, Tobin et al., 2008, Vandrovcova et al., 2010), many nominated loci for brain phenotypes are not functionally annotated. This evidence concerns the gene MAPT and Parkinson disease.