TNF and COVID-19: For example, affinity proteomics studies have identified distinct inflammatory phenotypes and enrichment of the NF-κB and type 2 interferon (IFN) signaling pathways as correlates of disease, highlighting associations with various soluble biomarkers, such as IFNγ, interleukin-1 (IL-1), IL-6 and tumor necrosis factor (TNF), which are typically upregulated in acute COVID-19 (refs. 12–14).