CIN developing from MSI in MMR-deficient CRC leads to formation of micronuclei, which can release genomic DNA fragments into the cytoplasm; this triggers a type I IFN response through the cGAS–STING pathway (Harding et al, 2017; Mackenzie et al, 2017). This evidence concerns the gene STING1 and cervical squamous intraepithelial neoplasia.