H6PD and Alzheimer disease: Importantly, the lower G6PDH activity (a pivotal enzyme from the oxidative branch of the pentose phosphate pathway also involved in the regulation of nicotinamide adenine dinucleotide phosphate (NADPH) and of the key antioxidant reduced glutathione, GSH) observed in brains from female mice with early AD-like pathology further support an increased oxidative stress, in agreement with the G6PDH inhibition in postmortem hippocampal regions [133] and prefrontal cortex synaptosomes [134] from AD human subjects.