DDB1 and glioblastoma: For all lineages of differentiation and all time points we determined the copy number of eight genes including CDK4, MDM2, EGFR, GINS2, GFAP, TP53, DDB1 and MDM4 all of which are known to localize to amplified genomic regions in neural progenitor cells during differentiation and to be amplified in human glioblastoma.