IL4 and nervous system disorder: Therefore, the protective role of IL‐4 may be detrimental to the developing brain.[71] Previous studies have demonstrated that neuroimmune responses in fetuses and newborns markedly differ from those observed in adults.[71, 72] Moreover, a pathogenic Th2 cell subset revealed by single‐cell RNA ‐seq may be correlated with disease severity.[73] In general, Th2 cells play a positive role.[74] In fact, Th2 cells have been shown to promote recovery in SCI and other neurological disorders by secreting protective cytokines.[8, 9, 10]