It is striking that the features that distinguish skin tumors developed by C-IKKα/TgAC mice, i.e., MMP-9 and VEGF-A upregulation and increased EGFR activation are the same that characterize the skin tumors arisen in mice lacking IKKα or expressing diminished levels of this protein [28, 29]. This evidence concerns the gene MMP9 and skin neoplasm.