The BCR-ABL fusion protein is an abnormal protein that results from a specific genetic abnormality known as the Philadelphia chromosome. This chromosome is formed due to a translocation between chromosome 9 and chromosome 22, leading to the fusion of the BCR gene from chromosome 22 with the ABL gene from chromosome 9. The resulting fusion gene encodes for a constitutively active tyrosine kinase protein, BCR-ABL, which plays a crucial role in the pathogenesis of certain cancers.
