MGMT and astrocytoma (excluding glioblastoma): Notably, in five tumors from four astrocytoma patients, CDKN2A/B homozygous deletions were accompanied with homozygous deletions of MGMT. Homozygous deletion of CDKN2A/B was less common in oligodendrogliomas as only one recurrent tumor presented this alteration in our entire cohort.