APLP2 and mild neurocognitive disorder: The expression of APP protein was reported to be elevated in muscle of human patients with MND and in a the SOD1-G93A mouse model of MND [27] over time as the disease progressed, however, we did not see any detectable changes in either APP and APLP2 protein levels in skeletal muscle of the SOD1-G37R mouse model for MND throughout disease progression.