To confirm the changes in macrophage gene expression level upon infection with M. avium or its isogenic 2D6 mutant from the DNA microarray data findings, real-time PCR analysis was used to amplify GRK4 (G-protein coupled receptor kinase 4), DGKD (Diacylglycerol kinase delta), both upregulated in the wild-type but down-regulated in the 2D6 mutant infected macrophages, and LCP2 (Lymphocyte cytosolic protein 2) down-regulated in wild-type but upregulated in the 2D6 mutant. This evidence concerns the gene GRK4 and infection.