We then compared total ERBB4 mRNA levels in 15 GBM samples paired with NNB biopsied from the contralateral hemisphere and found significantly lower ERBB4 mRNA levels in GBM than in paired NNB (p = 0.04) (Figure 2B), confirming reports that an overall reduction in ERBB4 mRNA is associated with GBM [10,11,29]. This evidence concerns the gene ERBB4 and glioblastoma.