We previously developed a panel of single chain antibody variable domain (scFv) based reagents that very selectively bind disease-related variants of tau, Aβ, TDP-43, and α-syn that are present in post-mortem validated human neurodegenerative disease brain tissue, but not in cognitively normal, age-matched human samples [11, 12, 30, 50, 53, 61]. The gene discussed is MAPT; the disease is neurodegenerative disease.