To further assess whether IGF2BP2 in macrophages plays a role in M2 polarization in vivo, we also used cockroach allergen (CRE) to induce allergic lung inflammation in bone marrow chimera mice (Figure 6b), in which M2 macrophages played a critical role as shown before.[32] Wild‐type (WT → WT) chimeras had more severe asthma pathologies than IGF2BP2‐deficient chimeric mice (IGF2BP2–/– →IGF2BP2–/–). This evidence concerns the gene IGF2BP2 and asthma.