TERT and neoplasm: Using deep sequencing (and targeted Sanger sequencing for the TERT promoter), we identified a set of early and potential driver variants (n = 12) already present in genes in primary O2005 which included IDH1 and TERT, but surprisingly not FUBP1 and CIC. Allele frequencies for 10 of these 12 variants was ≤ 50%, but increased for some variants indicating possible selection of tumor cell subpopulations in response to normal progression, treatment, or engraftment.