MET and osteosarcoma: The transforming role of the Met tyrosine kinase was first identified in the fusion protein Tpr–Met oncogene, experimentally induced in human osteosarcoma cells exposed to the mutagen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), causing translocation of part of Met gene on chromosome seven with the translocated promoter region (TPR) on chromosome one [13].