CHL1 and asthma: FLG encodes the filaggrin protein, which functions in differentiation of the epidermis and maintaining barrier function.[31] Common variants in FLG have been associated with atopic dermatitis[32–34], eczema[33,35–38], and asthma.[35,36] NCAM1 is a neural cell adhesion molecule involved in the proliferation of T-cells and dendritic cells, and is a member of the immunoglobulin superfamily.