Expression of candidate genes in response to stimulation of human EGFR. Realtime PCR was performed to determine expression levels of FOSL1 and EGR1 in the human melanoma cell line A375 (a) or expression levels of Fosl1, Egr1, Opn, Dusp4, and Taal6 in HER-transgenic melan-a cells (b), stimulated with EGF for the indicated times. The fold change of transcript, referred to the unstimulated controls, is indicated on the y axis. Murine and human β-actin were used as reference genes. Significant (p < 0.05) or highly significant (p < 0.001) regulation are marked by one or two asterisks, respectively (Student's t-test, paired, two-tailed).