Analysis of single-cell RNAseq (scRNA-seq) datasets also showed a significantly upregulated expression of CCL2/3/4 and IL-1β, as well as several members of the tumor necrosis factor superfamily (TNF, TNFSF10, TNFSF12, and TNFSF13B), by macrophages from patients with severe COVID-19 infection compared to those from patients with moderate infection and/or healthy controls. Here, TNF is linked to infection.