TNF and cystic fibrosis: The PBMCs were stimulated ex vivo with respiratory syncytial virus (RSV) and resulted in significantly higher levels of two cytokines (TNF-α and IL-6) by the CF group compared to the 0.2 g 2′-FL/L formula group and similar levels of these two cytokines between the BF and 0.2 g 2′-FL/L formula groups.