RAC1 and carcinoma: Massive up-regulation in vascular endothelial cells during angiogenesis in vitro and in vivo and in human carcinoma cells. Involvement in Gbg-mediated adherens junction assembly in endothelial cells. Regulation of VEGF-Flt1-dependent cell migration of endothelial cells and macrophages through direct interaction with Flt1 and activation of PI3K/Ak-Rac1.