In order to characterize intrahepatic cytokine production, the mRNA levels of interleukin (IL)-2, -4, and -10 and interferon (IFN)-gamma were semiquantitatively determined by reverse-transcription competitive polymerase chain reaction in liver specimens from patients with chronic hepatitis C (n = 23), chronic hepatitis B (n = 9), or primary biliary cirrhosis (n = 12) and normal liver (control) specimens (n = 12).IL-4 mRNA was undetectable.