For this, we compared gene expression of the epithelial cell marker EPCAM and immune cell markers CD45, CD74 and LYN (for macrophages, neutrophils, dendritic, natural killer, B and T lymphocytes) between COVID-19 positive and negative sample subsets representing the entire range of DDC and dACE2 expression (Fig 3A). The gene discussed is CD74; the disease is COVID-19.