MAPT and multiple system atrophy: Subsequently, utilizing a 4R tau substrate, they conducted RT-QuIC assays on post-mortem crude brain homogenates and CSF samples from patients with PSP, CBD, Pick’s disease, ALS, FTLD-TDP, FTDP-17, AD, PD, DLB, multiple system atrophy (MSA), central nervous system (CNS) lymphoma, and meningeal carcinomatosis [29].