ERBB2 and breast carcinoma: In addition, particular mutational patterns in the breast cancer subtypes have been found, for example, high frequencies of mutations in the PI3K/AKT pathway in luminal A tumours (>40% of cases) and high rates of TP53 mutations in HER2 and basal-like tumours (>70%), as shown in large genomic projects [10, 17, 60].