a, Turnover fluxes of glucose (n = 4 mice, mean ± s.d.) and lactate (n = 3 mice, mean ± s.d.) in anaesthetized mice. b, Normalized labelling of serum glucose, lactate, and glutamine in anaesthetized mice with 13C-glucose infusion (n = 4 mice; mean ± s.d.) and 13C-lactate infusion (n = 3 mice; mean ± s.d.). c, Steady-state whole-body flux model summarizing glucose and lactate interconversion and their feeding to the TCA (see Supplementary Note 4). Values are mean ± s.e.m.