Recent studies reported that mutations in the ATRX or DAXX genes that encode chromatin remodelling proteins essential for the deposition of the histone variant H3.3 at telomeric and pericentromeric regions of the genome influence the activation and maintenance of ALT in pNETs [313,455], paediatric glioblastoma [337], and a spectrum of other tumours [55,321,322]. Here, ATRX is linked to neoplasm.