Haas-Kogan et al (2005) showed that response to erlotinib was associated with EGFR expression and amplification. These correlations were stronger and statistically significant among the 29 patients with GBM (P=0.03 and 0.02, respectively). Among six responders with sufficient tumour tissue, none presented the EGFR truncated version known as EGFRvIII. Low levels of p-Akt expression was also associated with TTP (P<0.001). This evidence concerns the gene AKT1 and neoplasm.