However, the close relationships between filaggrin and filaggrin-2 suggested that the two proteins could play similar roles in the epidermal barrier function.20, 21 The recent descriptions of an association between FLG2 nonsense mutations and disease persistence in AD patients of African ancestry, and of a reduced expression of the protein in the epidermis of Caucasian patients, prompted us to look for filaggrin-2 function using RHE as an experimental model. The gene discussed is FLG; the disease is Alzheimer disease.