This gene encodes a regulatory protein that is involved in the positive regulation of ras proteins. Mutations in this gene are associated with Noonan Syndrome-9. [provided by RefSeq, Jul 2016],function:Promotes the exchange of Ras-bound GDP by GTP.,online information:Son of sevenless entry,similarity:Contains 1 DH (DBL-homology) domain.,similarity:Contains 1 N-terminal Ras-GEF domain.,similarity:Contains 1 PH domain.,similarity:Contains 1 Ras-GEF domain.,