Nathan K Cobb1, Caroline O Cobb2. 1. Department of Pulmonary and Critical Care, Georgetown University Medical Center, 3800 Reservoir Road, NW, 4 North Main Hospital, Washington, DC 20007, USA; Department of Health, Behavior and Society, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; MeYou Health LLC, Boston, MA, USA; Schroeder Institute for Tobacco Research and Policy Studies, American Legacy Foundation, Washington, DC, USA. Electronic address: nkc4@georgetown.edu. 2. Schroeder Institute for Tobacco Research and Policy Studies, American Legacy Foundation, Washington, DC, USA.