The source of the variability in CYP3A function is not known but our observation of a significant correlation between acute-phase response and the EBT 1/TMAX suggests that the pro-inflammatory cytokines, which are increased in malignancy (Heys et al, 1998; Barber et al, 1999; Martin et al, 1999), not only trigger the acute-phase response but also result in compromised drug metabolism by CYP3A in some cancer patients. The gene discussed is CYP3A4; the disease is cancer.