As expected, BO acquired a notable increase in the mRNA expressions of Mucin 2 (MUC2) and Mucin 3 (MUC3) but suppressed the mRNA level of matrix metalloproteinase-9 (MMP-9) in the colon of UC mice (p < 0.05 or 0.01, vs. DSS group) (Figure 2D). This evidence concerns the gene MMP9 and bronchiolitis obliterans syndrome.