Oncogenic Ras induces epidermal cell growth arrest. Induction of the JNK/Ap1 signaling cascade by expression of MKK7 overcomes Ras-induced cell growth arrest in a manner dependent on AP1 fucntion. We used microarrays to detail the global programme of gene expression in response to MKK7, Ras activation and AP1 inhibition Experiment Overall Design: To study the gene expression profile responsive to Ras and MKK7 expression. We used retroviral expression system to express LacZ, MKK7, Ras, DNc-Jun, MKK7+Ras, and MKK7+Ras +DNc-Jun in primary human keratinocytes, and then extract total RNA from the transduced cells for gene expression analysis.