ERBB2 and neoplasm: A subclonal ERBB2 (HER2) somatic missense mutation (p.I148M) was detected in the receptor ligand domain for both the pre-treatment tumour biopsy (~0.12 VAF) and patient matched brain metastatic tumour (~0.08 VAF) for Case #32 (Fig. 3b; Supplementary Table 6).