Western blotting and immunostaining confirmed the increased total GFAP (Fig. 1E and Supplementary Fig. S1C) and the co-expression of GFAP and TrkB (Fig. 1F) in colonic mucosal specimens of IBS patients, indicating that TrkB-related EGC activation might exist in IBS patients. The gene discussed is GFAP; the disease is irritable bowel syndrome.