Why IBD raises colon cancer risk, scientists finally found the missing link

Inflammatory bowel disease may raise colon cancer risk through a gut-to-bone-marrow signaling axis driven by TL1A, a protein elevated in inflamed guts. In mice engineered with and without TL1A signaling, only those with active TL1A developed tumors, indicating the gut inflammation can instruct the bone marrow to produce more neutrophils that migrate to the colon. TL1A triggers a cascade where gut‑resident immune cells release a secreted signal that travels to the marrow, prompting a surge of neutrophils with altered gene activity. Three antibody programs targeting TL1A are in Crohn’s and ulcerative colitis trials, though none were initially designed to address cancer.