NOX1 and neoplasm: The xenograft and isograft subcutaneous tumor models used in this study develop a myofibroblastic and collagenous stroma with similar structural properties to human tumors (18,24); we found that this can be suppressed pharmacologically using GKT137831, a small organic molecule of the pyrazolopyridine dione chemical class, which is a selective inhibitor of NOX1/4 and the first drug in this class of NOX inhibitors to enter the clinic.