Most recently, mouse NEC models have shown the importance of immunoglobulin A (IgA) for protecting against NEC in preterm infants (Gopalakrishna et al., 2019), validated the consequences of Paneth cell depletion in NEC (Lueschow et al., 2018), and begun to explore the mechanism underlying anemia and red blood cell transfusions in NEC (MohanKumar et al., 2019). This evidence concerns the gene CD79A and necrotizing enterocolitis.