However, echocardiography and plasma samples taken on day 3 of life in 53 infants, with a GA at birth below 28 completed weeks, revealed an association between large PDA (>1.5 mm) and increased pro-inflammatory (IL-1β, IL-8) and anti-inflammatory (IL-1Ra, IL-10) cytokines (125). Here, IL1B is linked to Patent ductus arteriosus.