TNFSF15 and primary biliary cholangitis: While PBC, CD and leprosy share some pathological features, such as granuloma formation24, the different effects of variance at 9q32 upon risk of these diseases, and the discovery of these risk variants in specific populations, mean that important questions on the overall role of 9q32 polymorphisms, specifically those affecting TNFSF15, remain unanswered.