Such higher free MG production by cancer cells or by transformed normal cells in culture may be due to the inhibiting effects of endogenous and/or exogenous causal agents on the activity of glyceraldehyde 3-phosphate dehydrogenase (GAPDH), which normally oxidize glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate. The gene discussed is GAPDH; the disease is cancer.