In particular, elevated levels of proinflammatory cytokine interleukin 6 (IL-6) in blood after birth [14], glycoprotein 130 (gp130, also known as IL-6 signal transducer) in cord blood [15] and reduced expression of IL-10 in placenta [17] were associated with risk of BPD. This evidence concerns the gene IL6ST and bronchopulmonary dysplasia.