When tissue tension creates a mutagenic niche.

In this issue of Cancer Cell, Hayward et al. show that fibrotic tissue tension creates a mechanically organized mutagenic niche. A stiff stroma activates epithelial STAT3, recruits macrophages, and drives NOX-dependent lipid peroxidation, generating diffusible aldehydes that damage epithelial DNA in fibrotic tumors and mammographically dense breast tissue.