Recent studies demonstrate that STAT3 could be a useful tumor marker of poor prognosis; however, given the tumor suppressive role of STAT3 in PTEN deficient tumors, it is important that future studies stratify GBM samples based on genetic background, as the relevance of STAT3 to tumorigenesis is a function of GBM genotype. This evidence concerns the gene STAT3 and glioblastoma.