Leaky membranes in aging liver cells release cancer-promoting factors that activate regulatory T cells, a new study demonstrates. High-fat diet weakens gut barrier function, resulting in the migration and accumulation of lipoteichoic acid in the liver, that is secreted by gut bacteria. Lipoteichoic acid stimulates the cleavage of gasdermin D protein that forms pores in the cell membrane through which cancer promoting IL-1β and IL-33 are released from liver fibroblasts.