NADK and cancer: In cancer cells, NADPH levels are controlled by several pathways, with the aim not only to contrast ROS production, but also in order to promote several metabolic reactions able to induce tumour proliferation, including NAD kinase (NADK), malic enzymes (ME) and NADP-dependent isocitrate dehydrogenases (IDH1 and IDH2) (Ju et al., 2020) but also glyceraldehyde 3-phosphate dehydrogenase (GAPDH).