CD79A and necrotizing enterocolitis: Conversely, in NEC-afflicted preterm infants, the gut shows a higher proportion of IgA-unbound bacteria, especially Enterobacteriaceae, compared to preterm infants without NEC.167 However, in an animal model, mouse pups nursed by IgA-deficient mothers showed disease susceptibility akin to formula-fed peers, despite maternal milk exposure.167 This finding highlights the pivotal role of maternal IgA levels or the proportion of IgA-bound gut bacteria for the protection of NEC.