GATA3 and neoplasm: In our series, we observed that a proportion of CDH1MT tumours also harboured clonal mutations known to be enriched in pure IDCs (MAP3K1, GATA3) alongside ILC-enriched mutations (TBX3) present in both the Neg and Ab components, suggesting that these tumours inherently harbour genomic features that are found to be enriched in both pure IDC and ILC tumours.