MMP9 and colorectal carcinoma: In support of the central role of NOX1 in CRC invasion and metastasis, upon NOX1 silencing we observed in Caco-2 cells that NOX1 is required for EGF-mediated: i) EGFR pathway activation, ii) upregulation of MMP-2 and MMP-9, and iii) cell invading activity.