CD44 and COVID-19: The patients’ stratification according to cardiovascular involvement showed a significant difference in the stimulated mRNA levels for ERAP1 (COVID-19 patients with cardiovascular involvement vs. controls, ANOVA Tukey post hoc test, p adjusted <0.05) and ERAP1, as well as CD44 (COVID-19 patients without cardiovascular involvement vs. controls, ANOVA Tukey post hoc test, p adjusted <0.05) (Supplementary Figure S9).