VAV1 and neoplasm: While tumors of Vav:Cre-Phd2fl/fl and control mice were equally apoptotic as assessed by CC3 IHC staining (Figure 6C), tumors from Vav:Cre-Phd2fl/fl mice showed aggravated tumor proliferation compared with their controls as assessed by IHC for PCNA (Figure 6D).