APOC1 and myeloid sarcoma: Two of the MS-specific upregulated proteins were present as transcripts in the human MS brain: apolipoprotein C-I (APOC1) was significantly upregulated in active lesions, and receptor-type tyrosine-protein phosphatase gamma (PTPRG) was significantly upregulated in all WM tissue (NAWM and lesions) (Fig. 7a).