APOE and chronic obstructive pulmonary disease: These peculiar side effects related with the deficiency of Apoe but not Ldlr, confer to Apoe−/− mice greater adaptability for studying several other diseases associated with inflammation and extracellular matrix degradation [12], such as Alzheimer’s [13, 14], erectile dysfunction [15], diet-induced steatohepatitis [16, 17], and recently also chronic obstructive pulmonary disease [18–21].