TLR4 and necrotizing enterocolitis: In addition, several studies have reported an increase in activation of Toll-like receptor 4 (TLR4) in infants who have developed NEC (Leaphart et al., 2007; Neal et al., 2013), and disruption of TLR4 genes have been associated with NEC development (Sampath et al., 2011, 2015).