IL13 and Nasal polyposis: Overexpressed IL-13 may be secreted from paracrine sources such as Th2 cells, ILC2s, and mast cells to induce nasal epithelium proliferation, implying that when the nasal mucosa is removed from the chronic inflammatory environment, it may reduce the abnormal proliferation of the self-repairment of nasal epithelium and ultimately reduce the formation possibility of nasal polyps.