Multicolor FISH analysis of LN-229 glioblastoma cells revealed a hyperdiploid karyotype with more than two copies of the long arms of chromosome 12 harboring the POLE gene at 12q24.33 and possibly of chromosome 19 harboring the POLD1 gene at 19q13.33 (Fig. 5a). This evidence concerns the gene POLD1 and glioblastoma.