Figure 1 (A) Representative western blots showing interleukin 21 receptor (IL21R) (upper blot), common γ chain (middle blot) and β‐actin (lower blot) in fibroblasts isolated from the colon of one control (Ctr), one patient with Crohn's disease (CD), one patient with ulcerative colitis (UC), from fetal gut fibroblast cell lines (CCD18CO) and from peripheral blood lymphocytes (PBL, used as a positive control). The right inset shows the quantitative analysis of IL21R/β‐actin protein ratio in fibroblasts isolated from seven controls, seven patients with Crohn's disease and seven patients with ulcerative colitis as measured by densitometry scanning of western blots. Values are expressed in arbitrary units (au) and indicate mean (standard deviation (SD)) of all experiments. (B) Representative electrophoretic gel showing reverse transcription‐polymerase chain reaction products for IL21R, common γ chain and β‐actin in RNA samples prepared from fibroblasts of one control, one patient with Crohn's disease, and one patient with ulcerative colitis, from CCD18CO and from PBL. TT, tube test, in which amplification was carried using RNA instead of cDNA. One of three separate experiments is shown.