NRP-1 protein expression in human polyps. The expression of NRP-1 in human colorectal adenoma was characterised as intensity of stain (0-2; 0: no expression, 1: moderate expression and 2: strong expression) or the percentage of the adenoma cells expressing NRP-1. The data is presented as mean ± SEM and split into tertiles according to butyrate concentration. The graphs demonstrate lower NRP-1 expression correlates with lower butyrate level and a significant difference is seen between groups (Jonckeere-Terpstra; p = 0.026). Post-hoc analysis (Mann-Whitney U test) identified significance between the low and high butyrate groups with NRP-1 expression intensity, but not with the percentage of expressing NRP-1.