IDH1 and cyclic hematopoiesis: Commonly observed genomic alterations previously reported in various types of CNS tumors, such as IDH1, IDH2, TP53, NF1, SMARCB1, FUBP1, and ATRX mutations, PTEN deletion, EGFR amplification, and 1p/19q deletion45, were also checked and found to be absent in CN.