The three genes that typify immune training—PFKB3 (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3), PGK1 (phosphoglycerate kinase 1), and LDH (lactate dehydrogenase)—were compared in CF challenged with SI/R. Here, PFKFB3 is linked to cystic fibrosis.