As previously reported, treatment of AD patients with dupilumab, a humanized monoclonal IgG4 antibody that binds to the IL-4Rα subunit of IL-4R type I and of IL-4/IL-13R type II, downregulated the expression of MMP12 in the skin of AD patients in a dose-dependent manner during treatment (31). This evidence concerns the gene MMP12 and Alzheimer disease.