A prospective study is suggested on a large number of Egyptian healthy controls and patients with liver cirrhosis to study the correlation between CYP3A4 mRNA titer in blood and the urinary ratio of 6 β-hydroxycortisol/cortisol in a trial to explain the wide variability in CYP3A4 activity among Egyptians. The gene discussed is CYP3A4; the disease is cirrhosis of liver.