Control of ferritin expression. The expression of ferritin is regulated at both the transcriptional and post-transcriptional levels by iron, cytokine release, chemokine production, lipopolysaccharide, prostaglandins, hormones, growth factors, second messengers, hyperoxia and hypoxia, and oxidative stress . Cytokines may also affect ferritin translation indirectly through their ability to induce nitric oxide synthase and, hence, increase nitric oxide (NO) (Figure 2) [11, 12]. NO, in turn, causes inhibition of ferritin translation. Complex feedback mechanisms between ferritin and cytokines in the control of pro-inflammatory and anti-inflammatory mediators: cytokines can induce ferritin expression; otherwise, ferritin can induce the expression of pro- and anti-inflammatory cytokines.