The MYB gene (MYB proto-oncogene, transcription factor) is a protein-coding gene located on chromosome 6q23.3. The encoded protein is a transcription activator, a DNA-binding protein that specifically recognizes the sequence 5'-YAAC[GT]G-3'. MYB transcription factors are highly conserved from plants to vertebrates, suggesting that their functions involve fundamental mechanisms in the biology of cells and organisms.
In humans, the MYB gene family is composed of three members: MYB, MYBL1 and MYBL2, which encode the transcription factors MYB, MYBL1 and MYBL2 (also known as c-MYB, A-MYB and B-MYB). A truncated version of MYB, the prototype of the MYB family, was originally identified as a product of the retroviral oncogene v-myb, which causes leukemia in birds. This led to the hypothesis that abnormal activation of MYB could also cause cancer in vertebrates.