JAG1 and melanoma: Similarly, aberrant activation of the NOTCH pathway is suggested by the alterations in several NOTCH pathway components, such as copy gains of the ligand JAG1, the receptors NOTCH4 and NOTCH2, the co-activator MAML2, and the targets HES7 and MYC. Among tyrosine kinases, we identified a region of amplification (7q31.2) in 40% of melanomas that contained the MET oncogene, which is involved in development and progression of melanoma [26].