Moreover, a significant increase in several cytokines associated with STAT3—including interleukin-15 (IL-15), interleukin-9 (IL-9), and interleukin-2 (IL-2)—was observed in fetal tracheal aspirates of CDH survivors compared to nonsurvivors following FETO. Here, IL9 is linked to congenital diaphragmatic hernia.