NOX1-deficient mice do not respond to GKT771 and exhibit reduced B16-F10 tumor growth associated with decreased production of angiogenic factors and minor effect of GKT771 on cancer cells in vitro. NOX1-deficient mice do not respond to GKT771 and exhibit reduced B16-F10 tumor growth associated with decreased production of angiogenic factors and minor effect of GKT771 on cancer cells in vitro. C57/BL6 and NOX1-deficient mice with established B16-F10 tumors were treated with GKT771 or vehicle (n = 6/8 mice per group). (A) Tumor size was measured in vivo with a caliper during the course of the experiment. (B) Tumor size and mass were measured ex vivo at the end of the experiment. Tumors and healthy lungs from WT and NOX1-deficient mice were isolated, and blood vascular endothelial cells (CD45−/CD31+/GP38−), lymphatic endothelial cells (CD45−/CD31+/GP38+), and macrophages (CD46+/CD11b+/F4/80+) were stained and sorted by flow cytometry. (C, D) The absolute numbers of the three cell populations in the lungs and tumors of WT (C) and NOX1-deficient mice (D) are shown. (E) PLGF was measured by ELISA in the plasma of mice bearing B16-F10 tumors in WT and NOX1-deficient mice treated with GKT771. Jimmy Stalin et al. LSA 2019;2:e201800265 © 2019 Stalin et al.