Activated MET receptor is subject to recycling from the plasma membrane through the endosomal compartment and back to the plasma membrane (Peschard et al. 2001, Hammond et al. 2001, Petrelli et al. 2002). In the recycling process, activated MET receptor is endocytosed, and the GGA3 protein directs it, via a largely unknown mechanism, through the RAB4 positive endosomal compartments back to the plasma membrane (Parachoniak et al. 2011). Endosomal signaling by MET during the recycling process appears to play an important role in sustained activation of ERK1/ERK2 (MAPK3/MAPK1) and STAT3 downstream of MET (Kermorgant and Parker 2008).