Expression of ATF-3 and ATF-4 genes was examined quantitatively by real-time PCR and changes in the expression of these genes in atherosclerotic lesions and in psoriatic skin were demonstrated. It was found that concomitant pathologies do not affect the expression of these genes. Opposite changes in the expression of ATF-3 and ATF-4 genes in atherosclerotic and psoriatic samples were revealed and a hypothesis was put forward that this parameter could be a criterion of pathological process in both diseases.