TNF and infection: During infection, recognition of pathogens by resident immune cells leads to the release of pro-inflammatory cytokines, such as TNF-α and IL-1β, which activate endothelial cells to express adhesion molecules (such as ICAM-1) and several other resident cell populations (e.g., glial and endothelial cells) to express chemokines (such as CXCL1 and CXCL2), guiding neutrophil migration [12,13].