CD4 and myeloid sarcoma: The most direct evidence of a role for A2ARs in the immunopathogenesis of MS comes from EAE animal studies, in which it has been shown repeatedly that knocking out A2ARs exacerbates the severity of EAE, as evidenced by greater motor paralysis, more infiltrating CD4+ T lymphocytes in the CNS and more demyelination in A2AR KO (A2AR−/−) mice in comparison with WT mice (23, 29).