Coronavirus disease 2019 (COVID-19), caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to a global pandemic. SARS-CoV-2 spike protein binds to angiotensin-converting  enzyme  2  (ACE2),  a  transmembrane  endopeptidase  on  host  cells  of  the  airway  epithelium  surface  for  invasion  and  infection;  therefore,  most  COVID-19  research  has focused on ACE2. Patients with chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis  are  reportedly  at  a  high  risk  of  COVID-19  morbidity  and  mortality,  regardless  of whether they have asthma.