This autoantibodies, which is relatively frequent and can be found in non-autoimmune rheumatic diseases, as monospecificity (anti-Ro52 antibody positive in the absence of anti-Ro60) [38–42] as only present in 2 (1.5%) MS patients, a prevalence unexpectedly low, given the reported high prevalence of ANA in MS, autoimmune nature of the disease, and the relatively high prevalence of anti-Ro52 abs in the general population; all three points raising the logical expectation of a higher percentage rate for this autoantibody’s specificity in MS. This evidence concerns the gene TRIM21 and myeloid sarcoma.