GPT and sarcoma: Both the molecular details of ALT activation (Cesare and Reddel, 2010) and the specificity for certain tumors, either with mesenchymal (sarcoma) or neuroectodermal (glioblastoma) origin (Heaphy et al., 2011; Mangerel et al., 2014; Louis et al., 2016) remain to be defined.