In path a, revefenacin was a drug for chronic obstructive pulmonary disease (COPD), which can help relax the lung muscles and help relieve cough and shortness of breath [55], while COPD has many potential negative interactions with COVID-19 [56] and abnormal expression of angiotensin converting enzyme 2 (ACE2) plays an important role in both COPD and COVID-19 [57,58]. This evidence concerns the gene ACE2 and chronic obstructive pulmonary disease.