CD38 and myeloid sarcoma: Next, expression of CD38 and HLA-DR was investigated (figure 3C,D), as these markers are known to be specifically upregulated on recently activated T cells and their expression is associated with viral clearance and recovery in healthy individuals21 38 and OCR-treated patients with MS.39 Several CD8+ T CM, EM, EMRA, and CD4+ T CM and EM populations were significantly activated in non-seroconverted OCR-treated patients with MS, whereas only CD8+ T CM cells demonstrated robust activation in seroconverted OCR-treated patients with MS (figure 3D–I).