Each year, about 500 children are diagnosed with a brain tumor in Germany. Pilocytic astrocytoma (PA) is the most common brain tumor in childhood and associated with a 10-year progression-free survival rate of 44% with standard of care chemotherapy. Although many PAs are cured by gross neurosurgical resection, approximately 20% are unresectable due to the tumor location and therefore tend to recur and/or persist despite radiotherapy or chemotherapeutic regimens. In PA patients who have failed standard chemotherapy regimens, radiotherapy is considered the standard of care. As a result, many patients experience significant treatment- and tumor-related morbidity, such as neuroendocrine, cognitive, and visual deficits as well as secondary tumors. Effective therapeutic approaches for PA therefore require a better and detailed description of the biological basis to discover potential new therapeutic agents for these entities. To reveal such underlying pathways we propose to establish an integrative phospho-proteogenomic approach of PAs for patients stratification and characterization of functional and therapeutically targetable pathways.