CNR1 and pulmonary fibrosis: ACPA itself, however, is unlikely to be used in clinical practice because of a short half-life and its lipophilic characteristic to easily enter the central nervous system, while the fibroblast-selective CB1R agonist like ACPA nanoparticles and agonistic antibodies to CB1R would be promising therapeutic drugs for pulmonary fibrosis that might be used clinically.