MUC1 and COVID-19: While ROS have been reported to be related to alveolar damage and coagulation abnormality [4,5], the present study did not find a significant association of serum uric acid level with serum KL-6 or plasma D-dimer level, and there was also no evidence of an effect of KL-6 or D-dimer on the relationship of serum uric acid level with severe COVID-19 progression.