Vildagliptin, another CD26/DPP4 inhibitor, ameliorates BLM‐induced pulmonary fibrosis (Liu & Qi, 2020), and Dpp4 deficiency reduces BLM‐induced fibrosis in the skin and lungs of mice (Soare et al., 2020), suggesting a functional participation of CD26/DPP4 in pulmonary fibrosis. Here, DPP4 is linked to pulmonary fibrosis.