Break point cluster region protein (Bcr) is encoded by the Bcr gene. The Bcr gene, mapping on chromosome22, was orginally identified by its presence in the chimeric Bcr-Abl oncogene. Although the BCR-ABL fusion protein has been extensively studied, the function of the normal BCR gene product is not clear. The protein has serine / threonine kinase activity and is a GTPase-activating protein for RAC1 and CDC42. A chromosomal aberration involving BCR has been found in patients with chronic myeloid leukemia.
