UBE4B and adult T-cell leukemia/lymphoma: We next examined the effect of UBE4B knockdown on the viability and proliferation of control Jurkat cells, Tax+ HTLV-1-transformed cell lines MT-2, HUT-102 and C8166, and the Tax- ATLL cell line TL-OM1 using CellTiter-Glo luminescent cell viability assay, which measures metabolically active cells by quantifying ATP levels.