ERBB2 and breast cancer: Targeted therapies, particularly directed at epidermal growth factor receptor (EGFR) mutations or anaplastic lymphoma kinase (ALK) translocations in non-small-cell lung cancers, human epidermal growth factor receptor-2 (HER2)-positive breast cancers and BRAF gene (v-Raf murine sarcoma viral oncogene homolog B1) mutant melanoma are being used with increasing frequency in patients with brain metastases.