Expression of HGF in human colon tissues. 4a Different expression of HGF (present only in epithelial compartment) in healthy tissues (A), ulcerative colitis (B), adenomas (C) and adenocarcinomas (D). The peak of immunoreactivity is in the healthy tissue. In contrast, in the dysplastic lesions, there is a drop in expression as the grade of dysplasia increases. The lowest expression is in UC cases (magnification ×400). 4b Expression of HGF in healthy tissues (HT), UC, AD and AC. In all groups HGF is significantly reduced respect to healthy tissues (mean ± SEM; **P < 0.01, *** P < 0.001). HT = healthy tissues; UC = ulcerative colitis, AD = adenomas, AC = adenocarcinomas.