TMEM119 and myeloid sarcoma: Studies suggested that TMEM119 is expressed exclusively on Iba1+CD68+ microglia and not on infiltrated Iba1+CD68+ macrophages within demyelinating lesions of MS that govern the edge of active lesions in MS (Zrzavy et al., 2017), indicating that microglial activation is related to disease development while its expression is absent in immature microglia (Satoh et al., 2016).