IFIH1 and dermatomyositis: To explore the adaptive immune responses in MDA5+ DM patients at the single-cell level, we performed scRNA-seq on peripheral B and T cells from seven active MDA5+ DM patients (MDA5+ DM-Act), three paired MDA5+ DM patients in remission (MDA5+ DM-Rem), and five IIM disease controls (Ctrl IIM) and four healthy donors (HD) (Fig. 1a, Supplementary Fig. 1a, b and Supplementary Table 1).