CREB1 and metastatic melanoma: Figure 3A demonstrates that CREB expression was reduced by 90% and 80% in A375SM and C8161-c9 cells respectively, as compared to cells transduced with non-targeting shRNA (NTshRNA). In line with the use of pathway inhibitors to decrease pCREB, CREB silencing via shRNA resulted in upregulation of AP-2α expression in both metastatic melanoma cell lines, confirming that CREB indeed acts as a negative regulator of AP-2α (Figure 3A).