RAS inhibitor Abd-7, a potent RAS-binding compound (Kd=51 nM), is a RAS-effector protein-protein interaction (PPI) inhibitor. RAS inhibitor Abd-7 interacts with RAS inside the cells, prevents RAS-effector interactions and inhibits endogenous RAS-dependent signaling. RAS inhibitor Abd-7 impairs the PPI of various mutant KRAS proteins with PI3K, CRAF and RALGDS as well as NRAS Q61H and HRAS G12V.