Prominent examples are ERBB2-amplified breast cancers [1] that respond to ERBB2 inhibition, BCR-ABL-translocated chronic myeloid leukemia patients that can be successfully treated with the ABL kinase inhibitor imatinib [2], [3], or EGFR-mutant non-small cell lung cancers (NSCLC) that are sensitive to treatment with the EGFR inhibitors erlotinib and gefitinib [4]. The gene discussed is ABL1; the disease is breast carcinoma.