CYP11A1 and pulmonary fibrosis: Currently, available data from in vitro and in vivo studies on various cell populations, including immunocompetent cells, allow us to consider vitamin D, its endogenous metabolites (including CYP11A1-mediated ones), and a number of its synthetic analogs, that are the agonists of vitamin D receptors (paricalcitol), as promising agents for the prevention and treatment of pulmonary fibrosis.