G6PD and neoplasm: Interestingly, the expression of glucose-6-phosphate dehydrogenase (G6PD), the rate limiting enzyme of the oxidative branch of the PPP, was upregulated in fructose A52 tumours (Fig. 1g and Supplementary Figure 6), while downregulated in the Huh7 fructose group (Fig. 1h and Supplementary Figure 8).