CUBN and Allergy: In this review, we highlight recent research advances in the understandings from mouse and human studies of protective and adverse impacts of maternal factors in the development of allergies and food allergy in children with a focus on maternal factors including allergens, immunoglobulins (Igs), immune complexes (IC), cytokines transferred from mothers to offspring in utero and via breast milk, together with genetic and environmental factors that could further facilitate the neonatal immune responses to allergens.