METRNL and allergic respiratory disease: In both blood and nasal samples, the most presented differentially methylated loci were annotated to ACOT7, EPX, KCNH2, SIGLEC8, TNIK, FOXP1, ATPAF2, ZNF862, ADORA3, ARID3A, IL5RA, METRNL, ZFPM1, making them possible candidates for allergic respiratory disease biomarkers.