Activation of inflammatory and itch pathways in dogs with AD and significant up-regulation of genes encoding for Th2 (e.g., IL-4, IL-5, IL-13, IL-31 and IL-33), Th9 (IL-9) and Th22 (IL-22) cytokines in acute canine AD skin lesions has been reported15 and their observation is also in agreement with our findings. Here, IL33 is linked to Alzheimer disease.