The unique characteristics of ALT include very long telomeres [10], telomere length heterogeneity [11], abundant extrachromosomal linear and circular telomere DNA [12], increased telomere-sister chromatid exchange (T-SCE) events [13], and the formation of ALT-associated promyelocytic leukemia (PML) bodies [14]. The gene discussed is GPT; the disease is leukemia.