The importance of FLG in the pathogenesis of AD is supported by the evidence that mice with Flg deficiency, e.g., flaky tail (Mattma/maFlgft/ft) mice and Flg mutant (Flgft/ft) mice on a proallergic BALB/c background, exhibit a spontaneous AD phonotype [7, 41–43]. Here, FLG is linked to Alzheimer disease.