CDKN2A and central nervous system cancer: Additional biomarkers, such as CDKN2A/B homozygous deletion, ATRX loss-of-expression, TERT promoter mutation, EGFR gene amplification and +7/-10 chromosome copy number changes, were officialy included in the CNS5 classification system to help designating glioma subtypes with more homogeneous clinical behaviors [3, 33, 34].