In this study, we sought to investigate the distribution and CD180 expression of peripheral blood B cell subsets, defined by CD27 and IgD staining in NMOSD and MS patients, and correlate the levels of natural anti-CS IgG with IgG antibody titers induced by bacterial infections described to play a role in the pathogenesis of NMOSD or MS. The gene discussed is CD180; the disease is myeloid sarcoma.