Telomeric maintenance is required to prevent cellular senescence of iPSCs and any other type of human cell. Predominantly, telomerase activity is responsible for this telomeric maintenance but alternative mechanisms also exist which can be induced in the absence of sufficient telomerase activity. The long-term effects of these alternative mechanisms on the cell are not yet fully understood and as such, telomerase activity may be better suited to the establishment of iPSC cell line for research or clinical purposes. However, there are many different methods used to detect telomerase activity and it may be necessary to use more than one to adequately characterize an iPSC's method of telomere maintenance. (Am J Transl Med 2018. 2:153-159).