FLG and Alzheimer disease: According to Thyssen et al. the important observations that put FLG into the centre of pathogenesis of AD are: impaired FLG values in skin with or without lesions in patients with AD, the fact that approximately 50% of patients with moderate or severe AD have at least one FLG mutation, that a decrease in the number of copies of FLG increases the risk of AD, that the decreased values of FLG were demonstrated in skin lesions despite the absence of FLG mutations, and that some of the existing therapies can repair FLG values (39).