MAPT and amyotrophic lateral sclerosis: For example, in one study the phosphorylated tau to total ratio was decreased in ALS CSF relative to healthy seniors,14 and in another study pTau181 in CSF was not correlated with pTau181 in plasma,15 Additionally, mass‐spectrometry based proteomic methods show that total tau (MAPT) is not elevated in CSF from ALS patients.16