GAPDH and infection: Likewise, fructose-1,6-diphosphatase, which catalyzes the conversion of fructose-1,6-diphosphate into fructose-6-phosphate in the glycolytic pathway [19] and glyceraldehyde-3-phosphate dehydrogenase which promotes ATP synthesis [20], were all significantly down-regulated after infection with S. agalactiae in the present study.