Ectopic expression of hTERT in human CD4⁺T-cell clones. Twelve CD4⁺ T-cell clones were transduced with hTERT-GFP, and the percentage of hTERT-GFP–expressing cells was monitored weekly by flow cytometry. Curves show the accumulation of hTERT-GFP–positive cells in the hTERT-transduced T-cell cultures of clones PEN J6, PEN J50, MoT-81, MoT-98, and MoT-72. Similar results were obtained upon hTERT transduction of the other clones mentioned in Table 1.