A cDNA encoding an HA-tagged version of the TEL-JAK2 protein encoded by a fusion gene, identified in a case of acute lymphoblastic T-cell leukemia, was inserted downstream of the Emu/SRalpha promoter/enhancer construct. The Emu/SRalpha enhancer/promoter allows high-level specific expression in lymphoid cells but only low to undetectable expression in nonlymphoid tissues. (J:166206)