Infection fighting cells from umbilical cord blood (left) and circulating blood three days after birth (right) from the same prematurely born baby. Umbilical cord blood has high levels of a factor, called neonatal NET inhibitory factor (nNIF), which inhibits a specific inflammatory response called NETs. Within two weeks after birth, nNIF levels drop and NETs can form. True to their name, they consist of a net-like substance that traps infectious agents like bacteria, as seen on the right. nNIF is showing promise as a potential therapy against harmful inflammation and sepsis.