The identification of recurrent telomerase reverse transcriptase (TERT) promoter mutations in 21 % of 91 medulloblastomas [13] is intriguing, since other mechanisms converging on increased telomerase activity including alternative lengthening of telomeres (ALT) [8] or mutations affecting the ATRX/DAXX complex are excessively uncommon in medulloblastoma [12, 25, 32, 34, 39]. The gene discussed is TERT; the disease is medulloblastoma.