Concerning the other AD protein hallmarks, evaluation of the diagnostic potential of cerebrospinal fluid (CSF) total (T‐tau) and phosphorylated tau (P‐tau181) has provided conflicting results [10, 11]; nevertheless, T‐tau might serve as prognostic biomarker reflecting the entity of motor neuron (MN) degeneration [12] similarly to serum levels of neurofilament light chain (NFL). Here, MAPT is linked to Alzheimer disease.