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). This evidence concerns the gene CSF1 and COVID-19.