ARAP1 is a 1450aa containing signaling protein, belonging to the centaurin family with SAM, ARF-GAP, RHO-GAP, ankyrin repeat, RAS-associating, and pleckstrin homology (PH) domains. In vitro, ARAP1 displays RHO-GAP and phosphatidylinositol (3, 4, 5) trisphosphate (PIP3)-dependent ARF-GAP activity that regulates ARF-, RHO-, and CDC42-dependent cell activities. It associates with the Golgi, and the ARF-GAP activity mediates changes in the Golgi and the formation of filopodia. It is thus involved in both signal transduction and cellular trafficking transport of a receptor protein involved in apoptosis. This protein is likely involved in the regulation of the cell-specific trafficking of TNFRSF10A and might thus affect the efficacy of TRAIL-induced apoptosis. ARAP1, an adaptor protein, is ubiquitously expressed in most of the tissues.