ERBB2 and breast cancer: Therapy personalisation has been a major game changer in modern oncology for many malignancies; a total of 50% of non-small-cell lung cancer patients with druggable oncogenic drivers [113], 50% of melanoma patients with druggable BRAFv600 mutations [114], 15–20% of breast cancer patients with HER2 positivity, and 10–15% of ovarian cancer patients with druggable DDR mutations benefit from specific targeted treatments [115].