Figure 4 illustrates immunostaining for iNOS, IL-1β, TNF-α and TGF-β RII in cheek pouches of hamsters subjected to 5-FU-induced oral mucositis (Figures 3c, 3g, 3k and 3o, respectively) on the 14th day of treatment compared with the weak staining observed in the Healthy control group (Figures. This evidence concerns the gene NOS2 and oral mucositis.