Bragsin1 is a potent, selective and noncompetitive inhibitor of the ArfGEF BRAG2, inhibits Arf GTPase activation, with an IC50 of 3 μM. Bragsin1 binds to PH domain of BRAG2, and is a noncompetitive interfacial inhibitor. Bragsin1 has no effect on the Sec7 domain of human ArfGEFs. Anti-cancer activity.