Tumour necrosis factor can bind to either p55 or p75 receptors and activates nuclear factor kappa B (NFkB) transcription factor. It promotes interleukin activity and can induce apoptosis. TNF α is procoagulant and can lead to thrombosis. TNF is produced by natural killer, T cells and macrophages. It enhances dendritic cell migration. It also increases adhesion molecule expression on vascular endothelium, allowing for increased permeability.