TNF and atherosclerosis: Among the inflammatory cytokines involved in the pathogenesis of atherosclerosis and associated with matrix degradation, the effect of 6 μm 27-OH and 5 μm HNE on IL-8, TNF-α, and IL-1β expression and protein levels were checked in U937 cells, by quantitative RT–PCR for up to 8-h treatment and by Bio-Plex® system after 24-h treatment, respectively.