MGMT and astrocytoma (excluding glioblastoma): The experiments using the glioblastoma cell line with unmethylated MGMT promoter (0%, MGMT-) and the astrocytoma, IDH-mutant, CNS WHO grade 4 (high grade astrocytoma, HGA) with low levels of MGMT promoter methylation (5%) were performed as planned, but the initial treatment period for the glioblastoma cell line with a high degree of MGMT promoter methylation (>50%; MGMT+) had to be discontinued.