IL1B and mucositis: Local application of 0.5 mM HPMC/GSNO for 14 days caused a considerable reduction in both iNOS and TNF-α immunostaining (Figures 3d and 3i, respectively) but had no effect on IL-1β immunostaining (Figure 4h) when compared with the untreated group comprising animals subjected to experimental mucositis and that received saline (Figures 3c and 3k, respectively).