CRK and glioblastoma: To translate these observations to explore the clinicopathological significance of EGFR, Crk, Crk pY251 and Abi1 protein expression in GBM, we performed Western blot analysis of patient GBM tissue samples (n = 32) versus matched normal tissue samples (n = 18), and consistent with the data using cell lines, GBM samples have up-regulated protein levels of EGFR (1.7 fold), CrkpY251 (1.5 fold), Crk (1.45 fold) and decreased level of Abi1-Iso2 (0.82 fold) (Figure 1G and 1H).