We recently showed that CD45+ leukocytes and pro-inflammatory cytokines in the cerebrospinal fluid (CSF) of subjects with amnestic mild cognitive impairment (aMCI), at a high risk for developing AD [15, 16], are present at levels equivalent to patients at the earliest stage of multiple sclerosis (MS), a central nervous system (CNS) autoimmune disease, confirming the presence of CNS inflammation [17]. Here, PTPRC is linked to myeloid sarcoma.