CD40 and myeloid sarcoma: The coexistence of iNOS+ or CD40+ cells along with microglia/macrophages expressing the anti-inflammatory marker CD163 [134] has also been observed at the rim of slowly expanding lesions (known as mixed active/chronic active lesions), supporting the absence of a well-defined pro- or anti-inflammatory phenotype for microglia/macrophages in such MS lesions [135].