CD14 and COVID-19: Next, we isolated peripheral blood mononuclear cells (PBMC) from hospitalized COVID‐19 patients with moderate or severe disease and from SARS‐CoV‐2 naïve healthy controls followed by positive selection of CD14+ monocytes which were differentiated to macrophages by incubation with M‐CSF (patient characteristics are provided in the Appendix Table S1 and Appendix Fig S1A).