FLG and Alzheimer disease: Previous immunohistochemical staining performed by Nemoto-Hasebe I et al. on two AD patients bearing p.Lys4021X showed profilaggrin/filaggrin peptides were remarkably reduced in the patients’ epidermis but real-time RT-PCR analysis revealed that mRNA expression of FLG was not reduced significantly [12], indicating that factors other than FLG mutations may lead to filaggrin deficiency in the epidermis of patients bearing mutation K4671X.