TNFSF15 and inflammatory bowel disease: By analogy, a noncoding genetic variant associated with lower gene and protein expression of TNFSF15 (encoding the inflammatory cytokine TL1A) in monocytes and macrophages increases IBD susceptibility45, but TL1A is upregulated both systemically and in the gut in patients with active IBD46,47, and anti-TL1A therapies have recently shown efficacy in IBD in phase 2 randomized trials (NCT05013905 and NCT04996797 (ref. 48)).