PPARA and myeloid sarcoma: Results revealed that upregulated proteins in MS-infected CSF were largely involved in metabolism (i.e., steroid hormone biosynthesis, pentose and glucuronate interconversions, ascorbate and aldarate metabolism, retinol metabolism, and amino sugar and nucleotide sugar metabolism), organismal systems (i.e., the PPAR signaling pathway, intestinal immune network for IgA production, NOD-like receptor signaling pathway, and C-type lectin receptor signaling pathway), and environment information processing (i.e., cytokine-cytokine receptor interactions) (Figure 4C).