Effect of low, medium and high IL-6 concentrations on PCNA, MyoD and myogenin protein levels in C2C12 cells. (A) PCNA protein levels in C2C12 cells treated with low, medium and high IL-6 concentrations for 24 h. (B) MyoD protein levels in C2C12 cells treated with low, medium and high IL-6 concentrations for 24 h. (C) Immunofluorescence staining for PCNA and myogenin in C2C12 cells treated with low, medium and high IL6 concentrations for 24 h. The experiment was repeated three times. Immunofluorescence images were taken at 100× magnification. Results are presented as mean ± standard error of the mean (S.E.M). Statistical analysis: ANOVA and Bonferroni post hoc test. * p < 0.05.