Computational predictions for SOS activating the Rac-p38 pathway. When SOS functions as both a RacGEF and an adaptor (A and D), an adaptor only (B and E), and a RacGEF only (C and F), the activation profile of Rac-p38 for cells with the DH-PH domain mutant SOS is between that for wild-type SOS and that for SOS1− SOS2− (A and D), the same as that for wild-type SOS (B and E), and the same as that for SOS1− SOS2− (C and F).