CDKN2A and astrocytoma (excluding glioblastoma): The prognostically unfavorable CDKN2A/B homozygous deletion is more common in grade 3 tumors (and especially in astrocytomas), which was found to be the case also in our material and which may contribute to a shorter survival in cohorts of WHO grade 3 tumors where this deletion has not been adjusted for (14, 18, 33, 34).