CRP and COVID-19: Among the ceramides, C22:0 ceramide had significant positive correlations with the CRP and D‐dimer levels in the COVID‐19 subjects; C24:0 ceramide had significant positive correlations with PT‐INR and APTT and a negative correlation with the fibrinogen level, while the direction of the correlations was negative in the subjects with non‐COVID‐19 infectious diseases.