To evaluate the suitability of MCEMP1 and HLA-DRA expression levels in discriminating severe COVID-19 from mild COVID-19 across multiple cohorts, we assessed the area under the curve (AUC) using combination of both MCEMP1 and HLA-DRA gene expression in the 7 independent transcriptomics study cohorts where blood was sampled immediately or at early time-points after hospital admission (Supplementary Table S1). Here, HLA-DRA is linked to COVID-19.