Increasing evidence implicates the IL-17/T helper 17 cells (Th17) axis in these processes: IL-17 concentrations are elevated in amniotic fluid, IL-17–producing cluster of differentiation 3 and 4 (CD3+CD4+) T cells accumulate in chorioamniotic membranes during preterm labor, and cord-blood Th17 signatures are enhanced in preterm neonates exposed to histologic chorioamnionitis [72,73,74]. The gene discussed is IL17A; the disease is chorioamnionitis.