The proto-oncogenec-mybis a cellular homolog of a viral oncogenev-mybfound in two independently derived avian acute leukemia viruses: avian myeloblastosis vn-us (AMV) and E26 leukemia virus (1 ). Themybgene is highly conserved in eukaryotes, and it usually consists of 15 exons spanning over 35 kb of genomic DNA (1 ).In humans,c-mybgene locus has been mapped to chromosome 6 (6q22-23) However,mybmRNA expressed in thymus contains transcripts originating from chromosome 17 (17q25), suggesting that an mtermolecular recombinant event may be involved in the formation of the mature protein (2 ).
