Ras-related protein Rap-2b （RAP2B） is a part of RAS-related genes family. RAP2B has a threonine residue at aa 61Unlike normal ras proteins which have a nontransforming glutamine residue at that position. The threonine residue makes the intrinsic GTPase activity for Rap2B lower， by this means allows RAP2B to exist in the activated state for a longer period of time than normal ras proteins. RAP2B is a platelet protein which is activated by thrombin and involved in platelet activation. RAP2B may be a candidate oncogene which takes part in carcinogenesis through activation of NF-kappaB pathway.
