ACE2 and chronic obstructive pulmonary disease: Overall, while it is unclear whether ever smokers with and/or without COPD may be at higher risk of SARS-CoV-2-infection (e.g., due to cigarette smoke -induced changes in numbers of the main ACE2-producing cells in the lung and/or increased SARS-CoV-2 S protein cleavage) if infected, they may be more severe due to underlying pulmonary inflammation and altered lung structure due to remodeling.