Filaggrin (FLG) is a key structural protein expressed in epidermal keratinocytes. Mutations in the filaggrin gene (FLG) are strongly linked to atopic dermatitis (AD) and allergic inflammation occurring later in life at distant body locations in AD patients. Keratinocytes secrete exosomes, small, lipid-rich membrane vesicles to communicate with distant cells, including within the immune system. The FLG gene was silenced in the HaCaT keratinocyte cell line by shRNA delivered using a lentiviral vector. HaCaT cells transduced with scrambled shRNA were used as a control.