Finally, even if MDA5 overreactivity, followed by increased production of IFN-alfa, can only be speculated in DM and mechanisms are still undisclosed, it is indeed true that titers of anti-MDA5 autoantibodies are directly related with disease activity and worse prognosis whereas their disappearance indicates disease control thanks to therapy [20]. This evidence concerns the gene IFIH1 and dermatomyositis.