We investigated the relationship between chronic inflammation and fibrosis in a mouse model of chronic colitis. Six weekly Trinitrobenzenesulphonic acid (TNBS) enemas were given to establish colitis and temporal changes in gene expression was elucidated over the next six weeks. Experiment Overall Design: After the six TNBS enemas, mice were sacrificed at 3 days (termed as TNBS-w6, n=6), 2 weeks (TNBS-w8, n=4), 4 weeks (TNBS-w10, n=5), or 6 weeks (TNBS-w12, n=4). The saline control groups were also sacrificed at week 6 (Saline-w6, n=5), week 8 (n=2) and week 10 (n=2). The last two sets were pooled as Saline-w10 (n=4). Two replicates of saline-w6 were analyzed. We compared Saline-w6 with TNBS-w6, and Saline-w10 with TNBS-w8, TNBS-w10, TNBS-w12, respectively.