In the present study we examined gene expression and glucose-6-phosphate 
dehydrogenase (G6PD) activity in leukemic cells isolated from G6PD normal and 
deficient subjects. The results have shown that G6PD activity strongly increases 
in G6PD normal leukemic cells as well as in G6PD deficient leukemic cells when 
compared to peripheral blood mononuclear cells (PBMC). Higher levels of G6PD 
gene expression were observed in leukemic cells from G6PD deficient patients 
compared to G6PD normal. A similar pattern of gene expression was also observed 
for 3-hydroxy-3-methylglutaryl coenzyme A (HMGCoA) reductase. These results 
support the hypothesis that G6PD deficient cell, in order to sustain their 
growth, must respond to the low activity of their mutant enzyme with an increase 
in quantity through an induction of gene expression.