Figure 4: Influence of titanium dioxide nanoparticles, titanium dioxide nanotubes, and titanium dioxide fine particles on cytokine production in 24h supernatants of C57BL/6 mice splenocytes culture. Cytokines interleukin-2 (a), interleukin-4 (b) are slightly elevated and interferon γ (c) significantly suppressed by the titanium dioxide nanomaterials. Cells alone (untreated cells) taken as control. Data are presented as mean ± standard deviation of three independent experiments. Statistical significance was defined as *P < 0.05, **P < 0.01