Figure 3: HSP70B' response by HepG2 cells exposed to different crystalline forms of TiO2 NPs. Histogram of HSP70B' response using HSP70B’ promoter-luciferase reporter plasmid (fold induction) by HepG2 exposed for 48 hours to different crystalline forms of TiO2 NPs (anatase form, rutile form, and mixed form, from left to right) at10 μg/mL. All values are presented as mean ± s.d. (n = 3).