VAV Family Genes (VAV1, VAV2, and VAV3) encode VAV proteins that respond to similar cell surface receptor tyrosine kinases as GEFs for Rho/Rac family GTPases, which activate pathways leading to actin cytoskeletal rearrangements, transcriptional alterations, cell differentiation, and/or cell proliferation. VAV proteins contain CH, DH, PH, SH2, SH3, and zinc-dependent phorbol-ester and DAG binding domains. VAV1 is expressed exclusively in hematopoietic cells, while VAV2 and VAV3 are more broadly expressed. (NCI) [ ]