MAPK8 and asthma: Compared with the OVA or OVA+PM2.5+NC‐EVs group, the levels of phosphorylated JNK, ERK and p38 were increased in the OVA+PM2.5 or OVA+PM2.5+let‐7i‐5p EVs group (Figure S23, Supporting Information), indicating that EV‐packaged let‐7i‐5p stimulated PM2.5‐induced asthma by activating the MAPK signaling pathway.