GTPase-activating protein for the ADP ribosylation factor family (Probable). Binds phosphatidylinositol 3,4,5-trisphosphate (PtdInsP3) and inositol 1,3,4,5-tetrakisphosphate (InsP4). Regulates the incorporation of CD63 and CD9 into multivesicular bodies (PubMed:38682696). {ECO:0000269|PubMed:10448098, ECO:0000269|PubMed:38682696, ECO:0000303|PubMed:10333475, ECO:0000305}. This is the function of ENSG00000105963 (ADAP1, ArfGAP with dual PH domains 1).