Telomerase activity levels have been shown to correlate with tumor progression in several malignancies. However, the genetic regulation of telomerase activity levels is not fully understood. The aim of the present study has been to identify a gene expression profile, predicting correlation with the telomerase-activity test. Ten human esophageal carcinoma cell lines were investigated using the telomerase activity assay (TRAPeze) Telomerase Detection Kit), followed by further characterization using the GeneChip Human Genome U133A 2.0 Array (Affymetrics Inc., USA), including 14 500 human genes. Telomerase activity levels were detected in all cell lines with a broad range of activity levels. Using a high correlation coefficient, r > 0.90, the following genes were found to be positively correlated with telomerase activity levels: N-myristoyltransferase 2; ribosomal protein L3; retinoblastoma-like 2 (pRb2/p130); and cyclin G2. Only one gene was negatively correlated with telomerase activity levels, zinc finger protein 207. In conclusion, the present microarray data provide primary validation data indicating possible candidates for prognostic and prediction factors in esophageal cancer in relation to telomerase activity.