Validation of microarray results of ten candidate genes by quantitative realtime PCR. RNA was extracted at indicated time points after HERmrk stimulation with hEGF. Expression of candidate genes was compared to unstimulated cells. The fold change of transcript, referred to the unstimulated control, which is set as 1, is indicated on the y axis. Mouse β-actin served as reference gene. Significant regulation (p < 0.05) is marked by an asterisk; two asterisks indicate highly significant regulation (p < 0.001) (Student's t-test, paired, one-tailed).