[18] The presence of tau along nerve fibers was demonstrated in patients with PD, multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and corticobasal syndrome (CBD) as well as healthy controls using IF, while only tau quantification by ELISA was able to discriminate PSP/CBD as tauopathies from the other disease entities. This evidence concerns the gene MAPT and tauopathy.