The analysis of substrate specificity demonstrated that the IgGs of two different BD patients and IgGmix (an equimolar mixture of five IgG from five different patients) effectively hydrolyzed MBP, but did not hydrolyze the other tested proteins (human and bovine serum albumin and rat collagen) under the same reaction conditions (Figure 3). The gene discussed is MBP; the disease is Behcet disease.