CD4 and systemic lupus erythematosus: Taube et al showed that ILC3s largely contribute to IL‐22 production in allergic airway disease, but Takahashi et al and Ito et al found that CD4+ T cells were the main producers of IL‐22 in the same model.29, 30, 31 Similarly, in SLE, Lin et al12 found that reduced serum IL‐22 levels might be a distinct feature of new‐onset SLE.