Angiogenesis inhibitors are shown to increase tumor oxygenation by the normalization of tumor vasculature in mice orthotopic models or by MRI analysis in patients.[6, 17, 18] In the present study, the expressions of HIF-1α and CA9, endogenous markers for tumor hypoxia, were not detected or were very low in four and three of the six cases for each (cases 3, 4, 5, and 6 for HIF-1α and cases 2, 3, 4 for CA9), and, therefore, the improvement of tumor oxygenation was suggested in five of the 6 tumors resected under Bev treatment. This evidence concerns the gene CA9 and neoplasm.