Based on our results, we conclude that one possible mechanism by which the tumors developed in the compound KCI transgenic mice with activated K-ras and Ink4a/Arf deficiency is in part due to the loss of miR-200 family, which leads to the activation of Jagged/Notch and NF-κB signaling pathway, resulting in the up-regulation of NF-κB target genes, such as MMP-9, c-myc, survivin, Bcl-2, cyclin D1, and COX-2 as summarized in the cartoon diagram (Fig. 7) and contributes to tumor aggressiveness. Here, MMP9 is linked to neoplasm.