In an asthma model mediated by allergens and environmental pollutant particles, NOTCH4 signalling up-regulated the expression of GDF15 in regulatory T cells, which promoted ILC2 expansion and activation through the Notch4-Wnt-GDF15 pathway [123] and provided a new therapeutic prospect for restoring lung immune tolerance and homeostasis [124]. Here, GDF15 is linked to asthma.