RAF1 and neoplasm: A leucine rich repeat protein which forms a complex with Raf and Ras. Initial studies have shown that when over-expressed, mammalian Shoc2/Sur 8 enhances Raf activation by promoting its interaction with Ras and thus enhancing the strength of ERK signaling (Li et al., 2000). Strikingly, inhibition of Shoc2/Sur8 causes inhibition of MAPK in tumor cells with mutant Ras (Rodriguez-Viciana et al., 2006).