A significant fraction of IBD patients have elevated levels in serum antibodies against Saccharomyces cerevisiae and polymorphisms in CARD9 (Caspase activation and recruitment domain 9) encoding CARD9, a critical intracellular molecule for immune responses against fungi, are associated with the development of IBD (Underhill and Braun, 2022). The gene discussed is CARD9; the disease is inflammatory bowel disease.