Another proposed mechanism concerns the CO-mediated regulation of glucose utilization, where CBS inhibition by CO drives the demethylation of phosphofructokinase/fructose bisphosphatase type-3 (PFKFB3), diverting glucose from the glycolytic towards the NADPH-generating pentose phosphate pathway, with implications in chemoresistance and oxidative stress resistance in cancer cells [24]. Here, PFKFB3 is linked to cancer.