Fig. 4. Ethoxyresorufin-O-deethylase (EROD) activity following a 24 h treatment with (a) BaP or (b) combinations of BaP (concentration indicated first) and PhIP. Data are means ± SEM, n = 3. Significance compared to the DMSO control (one-way ANOVA with Dunnett's post-test; **P ≤ 0.01, ***P ≤ 0.001, ****P ≤ 0.0001).