GPT and acute promyelocytic leukemia: Common characteristics of ALT activity in cells have been reported [34]: lack of telomerase activity, formation of ALT-associated promyelocytic leukemia (PML) bodies [35], high level of Telomere-sister chromatid exchange (t-SCE) [36], formation of circular extrachromosomal telomere repeats (ECTR or telomeric C-circles) [37] and highly heterogenous telomere length [38].