RT Journal Article SR Electronic T1 Tumour necrosis factor and Crohn's disease. JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 443 OP 448 DO 10.1136/gut.40.4.443 VO 40 IS 4 A1 S J Van Deventer YR 1997 UL http://gut.bmj.com/content/40/4/443.abstract AB