Interestingly, folate receptor β (FRβ, encoded by FOLR2) is highly expressed on lung macrophages from patients with idiopathic pulmonary fibrosis and from bleomycin treated mice, and has been exploited to selectively target therapeutic agents to suppress the production of profibrotic cytokines by activated macrophages [46, 47]. This evidence concerns the gene FOLR2 and idiopathic pulmonary fibrosis.