Figure 2: Cytokine determination in L. mexicana-infected macrophages. Levels of gene expression for each sample were normalized with β-actin RNA as internal control. Modulation was expressed relative to the untreated control using the method. The -axis intercepts the -axis at “1” to show the increase and the decrease of each cytokine compared to nontreated infected macrophages. Relative expression level for each cytokine was calculated according to = (CT test − CTβ-actin) treated − (CT test − CTβ-actin) untreated formula . Graph bars are mean ± SEM of three independent experiments, and statistical analysis was done comparing, for each time, treated versus nontreated macrophages; (*) , (**) , and (***) .