BCR and chronic myelogenous leukemia, BCR-ABL1 positive: These include BCR–ABL1, found in ~ 95% of chronic myelogenous leukemia (CML) patients [3]; TMPRSS2–ERG in ~ 50% of prostate cancers [4]; and DNAJB1–PRKACA, the hallmark and likely driver of fibrolamellar carcinoma [5].