miR-221-3p has been reported to promote B-cell proliferation and class switch recombination in vitro by targeting Foxp1 and Arid1a as regulators of Ig class switch recombination (CSR), as well as IgE production in allergic hypersensitivity, which suggested a role for this miRNA as a regulator of cell production of antibodies associated with allergy [19]. This evidence concerns the gene FOXP1 and allergic disease.