TLR4 and necrotizing enterocolitis: An earlier study using the piglet NEC model showed no increase in TLR4 expression in the intestine.243 Subsequently, White et al. developed an NEC model for mice in which Paneth cells are disrupted, which occurs independently of TLR4 signaling, as TLR4-deficient (TLR4−/−) mice presented a similar severity of NEC as wild-type mice.244 However, in the later study, the NEC model was induced at an older age (P14-P16), a stage at which TLR4 levels in the gut were quite low.62 Nevertheless, these findings suggest that the role of TLR4 in NEC may be more complex than initially thought.