FOXP3 and myeloid sarcoma: Although CD4+ T cells, both CD4+ Teff and CD4+FoxP3+ Treg cells, are the traditional primary actors in MS/EAE pathogenesis and immunoregulation, emerging evidence shows that CD8+ T cells also contribute to immunopathology and immunoregulation and can either exacerbate or mitigate brain inflammation during CNS autoimmunity (Mars et al., 2011; Mockus et al., 2021).