Indeed, profiling of peripheral blood mononuclear cells from people with RR-MS positive for the HLA-DRB1*15:01 susceptibility gene associated with heightened T-cell autoproliferation (Jelcic et al, 2018; Mohme et al, 2013) and undergoing treatment with natalizumab revealed significantly increased ROS levels in CD4+/CD25+/CCR7- TEM, compared to CD4+/CD25+/CCR7+ naive and central memory T cells (TCM). The gene discussed is CD4; the disease is myeloid sarcoma.