NOX1 and malignant colon neoplasm: Taken together, these studies demonstrate that although mRNA and protein expression are not sufficient for NOX1 activity, we have identified multiple colon cancer cell lines in which NOX1 was functional, including, LS513, LS174T, HT-29, and HEK293-NOX1 cells; thus these cells constitute pertinent model systems with which to study NOX1 tumor biology.