ERBB2 and chronic myelogenous leukemia, BCR-ABL1 positive: Well-understood examples include overexpression of ERBB2 in HER2+ breast cancer (Force et al., 2007) and the constitutively active oncogenic fusion protein BCR-ABL, which can cause CML (Force et al., 2007; Chen et al., 2008; Force and Kolaja, 2011).