Breast cancers in The Cancer Genome Atlas (TCGA)18 with both MYC amplification and TP53 alterations exhibit increased levels of CIN, DNA double-strand break signalling (for example, phosphorylated CHK2 (pCHK2)) and replication stress (for example, pCHK1) (Fig. 1a). Here, TP53 is linked to breast carcinoma.