Furthermore, mRNA expression of Tax and HBZ, which was recently identified in the 3'-long terminal repeat of the complementary sequence of HTLV-1 and has been suggested as a critical gene in leukemogenesis of ATLL [23], in HUT-102 and TL-OmI cells treated with I3C, was examined by RT-PCR. The gene discussed is HBZ; the disease is adult T-cell leukemia/lymphoma.