P-STAT5b, the activated form of signal transducer and activator of transcription 5, is frequently activated in malignant glioma cells and has been linked to tumor development and growth.37,38 We also previously found that P-STAT5B associates with tumor epileptogenicity in high-grade gliomas.39 In this current study, upregulation of P-STAT5B correlated with a smaller change on cognitive impairments, especially for the domain executive functioning, independent of tumor grade, volume, and location. Here, STAT5B is linked to central nervous system cancer.