BCR and chronic myelogenous leukemia, BCR-ABL1 positive: The amplification of upstream growth factor receptors takes place frequently in cancer, including the epidermal growth factor receptor (EGFR) in solid tumors [87] and BCR-ABL [fusion of the Abl1 oncogene gene on chromosome 9 to the BCR (breakpoint cluster region) gene on chromosome 22] in chronic myeloid leukemia (CML) [88].