MUC1 and COVID-19: Although there are various markers related to inflammation, alveolar damage, and coagulation abnormality, it has been reported that serum C-reactive protein (CRP), serum Krebs von den Lungen 6 (KL-6), and plasma D-dimer levels, respectively, are specific useful markers of those, being used similarly for COVID-19 cases [16,17,18].