The administration of anti-VEGF agents can result in reduced vessel irregularity, diameter and permeability and can transiently improve the delivery of oxygen.27 However, sustained anti-VEGF therapy can ultimately lead to loss of tumor vessels and increased hypoxia.28 In our study, we found that anti-VEGFR-2 therapy with DC101 did not significantly change intratumoral hypoxia when comparing similar-sized tumors; however, DC101 did appear to increase nuclear localization of HIF-1α in small tumors (200–300 mm3). This evidence concerns the gene VEGFA and neoplasm.