Furthermore, it is known that the increased thymic stromal lymphopoietin (TSLP) in the epidermis of AD patients activates extracellular-signal-regulated kinase [ERK, belonging to the mitogen-activated protein kinase (MAPK) family] and signal transducer and activator of transcription 3 (STAT3), leading to the inhibition of filaggrin expression [16]. This evidence concerns the gene STAT3 and Alzheimer disease.