All biomarker concentrations differed significantly between viral and non-COVID-19 pneumonia (Additional file 1: Table S10), but progranulin was significantly better in differentiating between COVID-19 and non-COVID-19 pneumonia (AUC = 0.91, 95% CI = 0.8–1.0 for progranulin vs. AUC = 0.79 for procalcitonin with 95% CI = 0.66–0.92 p =  < 0.001, see Table S8 and Fig. 8) and between COVID-19 and healthy individuals (AUC = 0.97, 95% CI = 0.91–1.03). This evidence concerns the gene GRN and COVID-19.