Abbreviations: Anti-TNF, anti- tumor necrosis factor; AZA, azathioprine ; BMI, body mass index; C. difficile infection, Clostredioides difficile infection; C. innocuum, Clostridium innocuum; CMV, cytomegalovirus; IBD, inflammatory bowel disease; UST, ustekinumab; VDZ, vedolizumab. The gene discussed is TNF; the disease is inflammatory bowel disease.