CCL22 and myeloid sarcoma: Interestingly, CCL22 may sustain MS development not only by allowing cells infiltration, but also being locally expressed: this chemokine has been found expressed by CNS activated microglia within demyelinated lesions, remyelinated areas, as well as in normal-appearing white matter, supporting the hypothesis of a potential switch across microglial phenotypes that may be predictive of incoming demyelination or remyelination processes [133, 134].