CNR1 and pulmonary fibrosis: Increased activity of the endocannabinoid/CB1R system was also reported to be parallel with the pathogenesis of pulmonary fibrosis and associated with the increased tissue levels of interferon regulatory factor-5, and the pathogenesis of pulmonary fibrosis, while CB1R inhibition, especially the combined CB1R/iNOS inhibition, has antifibrotic efficacy in bleomycin-induced pulmonary fibrosis (Cinar et al., 2017).