In order to evaluate whether the combination of DPP4 inhibitor and miR-23b-3p is more conducive to the remission of LPS-induced pulmonary fibrosis in vivo, we injected 100 nM sitagliptin alone or in combination with miR-23b-3p agomir into the tail vein of LPS-induced fibrotic mice. Here, DPP4 is linked to pulmonary fibrosis.