Based on these results, we classified all neuroblastoma samples into three subgroups according to their TMM status (Fig. 1C): (i) Telomerase-positive tumors (TEL[+]), defined by the presence of MNA, TERT RA, or high TERT expression, and absence of APB or C-circle positivity; (ii) ALT-positive tumors (ALT[+]), defined by the absence of alterations associated with telomerase activation and by the presence of concordant positive results in APB analysis and CCA; (iii) TMM-negative tumors (TMM[−]) defined by the absence of all these alterations. Here, GPT is linked to neuroblastoma.