These on-label therapies include BRAF kinase inhibitors such as dabrafenib and vemurafenib in cutaneous melanoma due to the high frequency of BRAF mutations, anti-human epidermal growth factor receptor 2 (HER2) therapy such as trastuzumab33 for breast and oesophageal cancers based on ERBB2 amplifications and poly (ADP-ribose) polymerase inhibitors in ovarian and breast cancer based on BRCA1/2 mutations. Here, ERBB2 is linked to breast cancer.