We first observed that the frequency of CD4 T cells was significantly increased in MDA5+DM patients compared with that in HDs (MDA5+DM vs. HDs: mean±SD [same for the following], 65.59 ± 14.31% vs. 53.85 ± 12.09%, P = 0.0215) (Figure 2). This evidence concerns the gene CD4 and dermatomyositis.