Similar biomarkers informing selection of targeted therapeutics exist for breast cancer (HER2 expression, trastuzumab), chronic myeloid leukaemia (BCR–ABL1 fusion, imatinib), metastatic melanoma (BRAF V600E, BRAF and MEK inhibitors), chronic lymphocytic leukaemia (17p deletion, venetoclax) and gastrointestinal stromal tumours (KIT expression, imatinib).77 The gene discussed is BRAF; the disease is B-cell chronic lymphocytic leukemia.