The gene is induced within 6 h by either cytokine, and its accumulation is observed upon induction with rIFN-gamma up to 5 d. The combined effect of the two cytokines is more than additive. rIFN-gamma also induces accumulation of X-CGD mRNA in immature myeloid cells from peripheral blood of chronic myeloid leukemia (CML) patients, whereas rTNF has almost no effect.