CNR1 and pulmonary fibrosis: In the present study, we found that CB1R expression dramatically increased in lung tissues and fibroblasts in response to experimental pulmonary fibrosis, but showed that its selective agonist ACPA exhibited marked antifibrotic effect both in vitro and in vivo models of pulmonary fibrosis, which was inconsistent with CB1R inhibition that ameliorated fibrosis (Bronova et al., 2015; Cinar et al., 2017; Correia-Sá et al., 2021).