ATRX and neoplasm: This is a heterogeneous group of supratentorial, mostly hemispheric, tumors (6/7, 86%) with clonal mutations identified in TP53 (4/7, 57%), ATRX (3/7, 43%), BRAF V600E (2/7, 29%), BCOR (1/7, 14%), CDKN2A (1/7, 14%), ZMYND11 (1/7, 14%), and EP300 (1/7, 14%) in tumor pairs (Fig. 1a).