The first cluster with severe lung involvement and a dramatically poor prognosis corresponded to the well-recognized “anti-MDA5+ RP-ILD.” In addition, two other overlapping forms were isolated: the “anti-MDA5+ arthro-DM,” with a good prognosis, and the “anti-MDA5+ vasculo-DM,” with an intermediate prognosis. The gene discussed is IFIH1; the disease is interstitial lung disease.