NOS2 and neurodegenerative disease: The differential exertion profiles between the postural soleus muscle (remaining recruited throughout during quiet standing) and the locomotor gastrocnemius muscle (providing fast forceful contractions) [52] may impact these muscle-specific findings in CIH and iNOS−/− mice and have likewise been implicated in massive muscle- (fiber-) specific differences in muscle aging or neurodegenerative disease [53–55].