IRAK4 and infection: Among the PRRs, TLRs appear to play a prominent role in neonatal responses to immunization/infection as suggested by: a) an association between TLR polymorphisms and altered responses to neonatal BCG immunization (53), and b) selective predisposition to bacterial infection in young but not older children with genetic defects affecting TLR downstream signaling (IRAK-4, MyD88) (54).