In human studies, in vitro polarization of peripheral blood mononuclear cells from patients with mild-to-moderate asthma shows that cells from female donors are more prone to acquire a classical M2 phenotype in response to IL-4 or IL-13, characterized by higher CD206 expression and increased levels of selected M2-associated chemokines, together with upregulation of IL-4Rα and relevant chemokine receptors (Becerra-Díaz et al., 2021). Here, MRC1 is linked to asthma.