SMAD2 and familial hypercholesterolemia: This study demonstrates the pulmoprotective effects of atorvastatin and ezetimibe treatment on hypercholesterolemia-induced PF caused by reducing serum lipid levels and oxidative stress, reversing the balance between pro-inflammatory and anti-inflammatory mediators, downregulating TGF-β-SMAD2/3, and upregulating MMP-19.