Baseline HE4 level was significantly higher (P < 0.0001) in critically ill (524.7 [300.1–1153.0] pmol/L) than severe COVID-19 subjects (157.4 [85.2-336.9] pmol/L) and in mild SARS-CoV-2 infection (46.7 [39.1–57.2] pmol/L). This evidence concerns the gene WFDC2 and COVID-19.