Schematic of RAS pathway features identified in this study. Among them are new, paralog-specific RAS/effector GI and PPIs, heterogeneity in GIs between MAPK pathway components, new roles in membrane dynamics for the RAS effectors RIN and RADIL, a striking intersection between RAS and RAP signaling, and synthetic lethal GIs between RALA and RALB and between RAP1GDS1 and RHOA that are contingent on KRAS activity.