FLG and allergic asthma: The epithelium plays an important role in the inception and development of asthma, particularly in non-allergic asthma, through the activation of type 2 innate lymphoid cells (ILC2) [36] and SNPs in filaggrin could compromise skin barrier function, increase penetration of allergens, reduce inflammatory threshold levels to skin irritants and allergens and increase the risk of sensitization [37].