On the other hand, cancer cells need maintenance of telomeric repeats in order to divide indefinitely and they achieve that by activating telomere maintenance mechanisms such as telomerase activity in the majority of tumors, or less frequently, activating alternative mechanisms of telomere lengthening based on homologous recombination between telomeric sequences (Alternative Lengthening of Telomeres or ALT) [20]. This evidence concerns the gene GPT and cancer.