CNR1 and pulmonary fibrosis: Overactivity of the endocannabinoid/cannabinoid receptor 1 (CB1R) system contributes to the development of multiple fibrosing interstitial lung diseases, such as IPF (2), Hermansky-Pudlak syndrome pulmonary fibrosis (HPSPF) (3, 4), and radiation-induced PF (5).