Considering that the balance between the consumption of NADPH via NOX [25], and the regeneration of NADPH by NADPH regenerating enzymes, e.g., G6PDH, within the cytosol, may overall depend on metabolic/redox state of the cell, we suggest that NNT, enzyme providing a link between the NADP/NADPH and NAD/NADH pools and the proton motive force, may have a very important role for redox metabolic regulation in CF. The gene discussed is H6PD; the disease is cystic fibrosis.