CD4 and dermatomyositis: found that compared with skin from the healthy controls and peripheral blood mononuclear cells (PBMCs) of patients with DM, the inflammatory infiltration of CD4+ T lymphocytes in the skin lesions in DM patients increased, and CD4+ T lymphocytes significantly expressed cannabinoid type 2 receptor (CB2R) and also produced interleukin (IL)-4, IL-31, interferon (IFN)-γ, and IFN-β.