There are multiple reasons underlying smokers’ inherent risk to COVID-19-related adverse outcomes, including the effects of cigarette smoking on: the immune system [3], which renders smokers susceptible to viral and other infections [4,5]; airways and lungs, which results in increased airway secretions, impaired mucociliary clearance, increased permeability of airway epithelium, and airway inflammation [6]; and upregulation of the angiotensin-converting enzyme-2 (ACE2) receptor in both current and former smokers [7]. This evidence concerns the gene ACE2 and COVID-19.