To further address the potential functional role of the MC proteases, the triple protease knockout lacking the three major proteases, i.e., mMCP-4, mMCP-6 and CPA3 [49] in comparison to the single knockout strains, would be highly interesting to evaluate in the MC903-induced AD-model, with varying doses of 1 to 4 nmol of MC903 and in mice on both the C57BL/6J and the BALB/c genetic backgrounds. The gene discussed is CPA3; the disease is Alzheimer disease.