BMP7 and cystic fibrosis: To further test the hypothesis that ILC2-derived BMP-7, an anti-fibrosis factor secreted by ILC2s upon IL-33 stimulation 44, 45, could antagonize TGF-β-induced CF activation, we isolated primary mouse CFs and cultured the cells with Saline, IL-33, or ILC2-CM for 24 h in the presence or absence of TGF-β1.