In the ongoing coronavirus disease 2019 (COVID-19) pandemic, some unique clinical features have been described [1]. In a report of 44,672 cases from China, a case fatality rate of 2.8% for males versus only 1.7% for females was observed [2]. It has been hypothesized that this may be due a higher prevalence of comorbidities among males, in particular the rate of smoking, which is reported to be 52.1% in men and 2.7% among women in China [3]. However, decreased levels of angiotensin converting enzyme 2 (ACE2), the reported host receptor of the virus responsible of COVID-19 (severe acute respiratory syndrome coronavirus 2; SARS-CoV-2), are observed in smokers [4,5].
