SORT1 and Alzheimer disease: Three studies (to the best of our knowledge) have analyzed the 100 kDa sortilin protein in postmortem human brains, with its levels found either preserved in AD patients and subjects with mild cognitive impairment relative to people with normal cognition at death (Mufson et al., 2010), or elevated among AD relative to control elderly (Finan et al., 2011; Saadipour et al., 2013).