The E3 ubiquitin ligase CBL can bind to the MET receptor either indirectly, through GRB2, or directly, through phosphorylated tyrosine Y1003 of MET (Peschard et al. 2001, Taher et al. 2002, Peschard et al. 2004). The kinase responsible for Y1003 phosphorylation is not known. Y1003 has not been reported as a MET autophosphorylation site, and is implicated as a possible PKC-alpha target (Zhao et al. 2013). As CBL-mediated ubiquitination of MET happens in response to HGF stimulation (Taher et al. 2002, Abella et al. 2005), it is likely that MET autophosphorylation precedes MET phosphorylation at Y1003.