Based on our prospective approach regarding the disease phenotype and the absence of anti-flotillin-1/2 in the controls, as well as based on the retrospective confirmation in a large cohort of pre-diagnosed MS patients, the flotillin-1/2 heterocomplex seems to be a B cell autoantigen in a subset of about 1–2% of MS patients. This evidence concerns the gene FLOT1 and myeloid sarcoma.