Telomerase activity in HD samples and in an HD-derived cell line. The level of telomerase activity was analyzed at 0.28 μg/assay. Lanes 1, 2, and 5, HD samples with eosinophilia that exhibited undetectable telomerase activity. Lanes 3 and 4, 2 telomerase-positive HD samples without eosinophilia. Lane 6, the HD-derived cell line KM-H2. The amplification of ITAS was almost competed out by the telomerase products formed by KM-H2.