BRAF and breast cancer: Examples of targeted therapies already in clinical use include approaches that exploit oncogene addictions, such as the increased sensitivity of BRAF mutant melanomas to BRAF inhibitors (Chapman et al., 2011), and approaches that exploit non-oncogene addiction/synthetic lethality, such as the sensitivity of BRCA1/2 mutant ovarian or breast cancers to PARP inhibitors (Lord and Ashworth, 2017).