NOTCH signalling can be transiently activated during stress-induced senescence (e.g. oncogene- and DNA damage-induced senescence)9 but also plays important roles during development and in cancer, thus ‘lateral induction’ of NOTCH activity through JAG1 could affect chromatin structure in various biologically relevant scenarios involving epithelial and/or fibroblast cells. This evidence concerns the gene JAG1 and cancer.