Article Cancer DNA methylation DNA methylation age Epigenetics Gene expression Glioblastoma Integrative classifier Karnofsky Performance Status MAPK signaling Machine learning Molecular subtypes algorithm area under the curve controlled study cost effectiveness analysis cytokine release diagnostic test accuracy study differential gene expression epidermal growth factor receptor epigenetics gene activation gene control gene expression gene expression profiling gene ontology glioblastoma hierarchical clustering high throughput analysis human