Peptidoglycan (PGN), a well-established activator of NOD1/2 signaling, has been detected in systemic circulation of healthy individuals and within demyelinating lesions of multiple sclerosis (MS) patients, as well as in phagocytes of MS animal models (Schrijver et al., 2001; Visser et al., 2006; Branton et al., 2016). This evidence concerns the gene NOD1 and myeloid sarcoma.