Several studies have shown that women living in more deprived areas are more likely than those living in less deprived areas to be diagnosed with oestrogen receptor negative (ER−) and triple-negative (ER−, progesterone receptor negative (PR-), and human epidermal growth factor receptor-2 negative (HER2−)) breast cancers (TNBC) [18, 22, 23]. Here, ERBB2 is linked to breast cancer.