The observation that ATRX/DAXX mediates recruitment of H3.3 to telomeres is consistent with the finding that mutations in H3.3 may also be associated with ALT in pediatric glioblastomas [17], [45], which suggests that ATRX, DAXX, and H3.3 act in the same pathway to repress ALT. Here, GPT is linked to glioblastoma.