(27) observed significantly lower transcript levels for elafin, secretory leukocyte proteinase inhibitor (SLPI), canine beta-defensin 1 (CBD-1), canine beta-defensin 103 (CBD-103), and canine beta-defensin 122 (CBD-122) in both lesional and non-lesional skin of dogs with AD compared to healthy skin. Here, SLPI is linked to Alzheimer disease.