STZ still led to increases in the protein levels of MLCK, ROCK1, and p-MLC in the colonic mucosa compared to vehicle treatment, but RS67333 did not block the diabetes-induced increases in the protein levels of MLCK, ROCK1, or p-MLC in the colonic mucosa of 5-HT4R KO mice (Figure 6). This evidence concerns the gene HTR4 and diabetes mellitus.