TNF and atherosclerosis: Moreover, in the immune and inflammatory pathways promoting atherosclerosis, activated T cells are involved which are a source of RANKL and pro-inflammatory cytokines (such as tumor necrosis factor α (TNF-α), interleukin-1 (IL-1), and interleukin - 6 (IL-6)), that up-regulate RANKL expression (6, 12, 49).