Telomerase activity was detected by TRAP in parental HeLaS3 and AGO2KO cells. 293T cells were used as a positive control. As negative controls, telomerase was heat- inactivated in cell extracts, in the last lane no cells were added in lysis buffer. Intensity of the telomerase products (6 bp-ladder) was determined by ImageLab Software (Biorad) and normalized with the intensity of the Internal Control (IC) (n=3 experimental replicates). 