However, the dominant feature of intestinal fibrosis and stenosis in the CD-like SAMP1/YitFc ileitis model as well as in induced murine fibrosis models (active TGFB1 adenoviral transduction, Ship−/−, Il10−/−) is hypertrophy of the muscularis propria with only minimally increased extracellular matrix. Here, TGFB1 is linked to fibrosis.