ERBB2 and chronic myelogenous leukemia, BCR-ABL1 positive: The erbB-2 expression levels in the normal and CML samples were detected by IHC using two antibodies against different regions of the erbB-2 protein: CB11 antibody, which has affinity for the intracellular region (CB11/int); and CBE356 antibody which has affinity for the extracellular region (CBE356/ext).