The effect of TMPyP4, the well established anticancer telomerase inhibitor on genome wide expression of genes, analyzed across different cell-lines, was investigated Keywords: Comparative gene-expression profiling Cells were treated with TMPyP4 for 48 hours before RNA isolation. Untreated cells were taken as controls and the TMPyP4 treated cells as treatments. Experiments in each cell-line (A549 and HeLa S3) were replicated four times.