RAC3 is a GTPase which belongs to the RHO family of small GTP-binding proteins that regulate a diverse array of cellular events, including the control of cell growth, cytoskeletal reorganization, and the activation of protein kinases. RAC3 is primarily expressed in brain and is proposed to play a specific function in neuronal cells. Depletion of RAC3 induces stronger cell adhesion and dramatically increases the outgrowth of neurite-like protrusions whereas overexpression of RAC3 results in a contractile round morphology. RAC3 can exert its function through negatively affecting integrin-mediated cell-matrix adhesions. RAC3 shares with RAC1 the ability to interfere with cadherin-mediated adhesion.