SPRY2 and central nervous system cancer: Spry2 expression is upregulated in patients with highly malignant gliomas (GBM) which correlates with reduced overall survival supporting previous findings that gliomas with high expression of Spry isoforms (Spry1, Spry2, and Spry4) and low expression of NF1 and PTEN are associated with poor prognosis as compared to tumors with a reversed expression pattern [29].