G6PD and breast cancer: Together, these data suggest that the ERRα metabolic target genes, such as genes involved in OXPHOS, the TCA cycle, and ROS detoxification, and key enzymes involved in PPP and purine biosynthesis pathways, such as G6PD and GART, respectively, are higher in the basal-like breast tumours of overweight/obese breast cancer patients compared to those of lean patients.