Dihydroartemisinin (DHA), an active metabolite of artemisinin and the most potent anti-malaria drug, is also used to treat autoimmune diseases such as systemic lupus erythematosus (SLE) and psoriasis. Since the first report of the immunomodulatory effect of DHA in the 1990s, there has been increasing evidence that DHA beneficially regulates the host-immune systems after administration. However, the potential mechanism remains to be clarified. The team of Prof. Qijun Chen constructed the first single-cell atlas of DHA-regulated splenic immune cell subsets and revealed, using single cell RNA sequencing along with cellular and histological approaches, that DHA regulated splenic immune cell heterogeneity through SOD3-JNK-AP-1 axis.