Furthermore, PAC detection of the EGFRvIII transcript isoform in clinical glioblastomas was determined by the overall expression level of EGFR transcripts, that was near the limits of linear detection in all five EGFRvIII glioblastomas, but also by the ratio of the EGFRvIII isoform versus wild-type EGFR transcripts (Fig. 3B). This evidence concerns the gene EGFR and glioblastoma.