TIE1 and neoplasm: However, although pSico-Flk-1 treatment inhibited significantly tumor angiogenesis in both wild-type/Tie1-Cre+ and β3-null/Tie1-Cre+ mice (P<0.05), pSico-Rac1-treatment did not affect tumor angiogenesis in wild-type/Tie1-Cre+ but did inhibit tumor angiogenesis significantly in β3-null/Tie1-Cre+ mice (Figure 3B).