Using transplantable metastatic tumour models of TNBC, Bakhoum, Ngo et al. [13] recently demonstrated that CIN enriches tumour cells for epithelial–mesenchymal transition (EMT)-related gene expression, supporting metastatic dissemination, in a cGAS–STING-dependent manner [13]. The gene discussed is STING1; the disease is cervical squamous intraepithelial neoplasia.