MAPT and amyotrophic lateral sclerosis: Furthermore, a study aiming to distinguish individuals with ALS from controls found that CSF TDP-43, total tau (TT), and tau phosphorylated at threonine 181 (TP-181) in a ratio of (TDP-43 × TT)/TP-181 increased the sensitivity from 0.72 to 1.00, the specificity from 0.77 to 0.92, and the AUC from 0.75 to 0.97 compared to measuring TDP-43 alone [123].