Activation of EPH receptors triggers the local activation of T-lymphoma invasion and metastasis-inducing protein 1 (TIAM1) and this in turn activates RAC1 (Yoo et al. 2010). RAC1 signaling is positively linked to EPH:ephrin (EFN) internalization but the exact link to clathrin endocytosis machinery remains unclear. TIAM1 co-localizes with the ARP2/3 complex at sites of actin polymerization. RAC1 activated by TIAM1 then subsequently activates the ARP2/3 complex proteins leading to actin polymerization (Ten Klooster et al. 2006).