Figure 4: Expression of chemokines in A549 cells line after Salmonella infection. The Y axes show the fold change in expression that was calculated according to the standard formula 2(En-Rn)-(Et-Rt), where En is the ct of the experimental gene in the normal sample, Rn is the ct of the reference gene in the normal sample, Et is the ct of the experimental gene in the treated sample and Rt is the ct of the reference gene in the treated sample. qRT-PCRs were repeated on three different biological replicates using as endogenous control for GAPDH gene and fold expression changes were averaged [40] (P<0.0001).