CRK and glioblastoma: Based on the range of expression of ABI1 and CRK in human GBM samples, we hypothesized that the low Abi1/high Crk signatures observed in a subset of human GBM may represent a biologically distinct subset that favors a more aggressive phenotype, we selected cases with high levels of CRK and low levels of ABI1 based on RNA-Seq data deposited into TCGA, and compared their gene expression to cases with intermediate levels of CRK and ABI1, which would identify altered phenotypes when Crk and Abi1 interaction is dysregulated or uncoupled (Supplementary Figure S2A).