SWAP70 is a 585aa regulatory protein belonging to the pleckstrin-like family with a PH domain essential for phosphatidylinositol 3,4,5-trisphosphate binding. SWAP70 acts as a link between the recognition of specific switch regions and causation of a DNA break and is involved in both nuclear events and in signaling B-cell activation. As a guanine nucleotide exchange factor (GEF) it transduces signals from tyrosine kinase receptors to RAC, independent of RAS. As a multiple functional signaling protein, and a component of the SWAP enzyme complex, it mediates signaling of membrane ruffling by tyrosine kinase growth factor receptors, actin cytoskeleton and cell protrusion. It is widely expressed in most tissues, mature B-cells, including those associated with mucosa-associated tissue and bronchus-associated tissue, monocytes and macrophages.