ERBB2 and breast neoplasm: For example, oncogene addiction effects, such as the increased sensitivity of ERBB2 (HER2)-amplified breast tumors to ERBB2 inhibitors (Hynes and Lane, 2005), can be clinically exploited, as can non-oncogene addiction effects, such as the synthetic lethal relationship between BRCA1/BRCA2 mutations and PARP inhibitors (Lord et al., 2015).