Members of the RAS superfamily of small GTP-binding proteins, as RAC1, appear to regulate a diverse array of cellular events, including the control of cell growth, cytoskeletal reorganization, and the activation of protein kinases (PKs).
References
Sherman LS, Gutmann DH. Merlin : hanging tumor suppression on the Rac. Trends Cell Biol. 2001 Nov ;11(11):442-4. PMID : #11684412#