The adapter protein GAB1 is involved in recruitment, through CRK and related CRKL proteins, of guanyl nucleotide exchange factors (GEFs) to the activated MET receptor. MET-associated GEFs, such as RAPGEF1 (C3G) and DOCK7, activate RAP1 and RAC1, respectively, leading to morphological changes that contribute to cell motility (Schaeper et al. 2000, Sakkab et al. 2000, Lamorte et al. 2002, Watanabe et al. 2006, Murray et al. 2014).