Crohn’s disease is characterized by the infiltration of inflammatory and immune cells (e.g., mast cells, neutrophils, T-lymphocytes, and macrophages) that interact and release certain enzymes, e.g., MPO and cytokines etc. Intestinal specimens biopsied from Crohn’s patient have shown a transmural chronic inflammation with upregulated MPO and cytokines (e.g., TNF-α, IL-1β, and IL-6) (Ligumsky et al., 1990; Gross et al., 1992; Reinecker et al., 1993; O’Hara et al., 2007). This evidence concerns the gene MPO and Crohn disease.