Hedgehog gene alterations were characteristic of medulloblastoma, mitogen-activated protein kinase (MAPK) and phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/Akt pathway alterations were typical in glioma and glioblastoma, and DNA repair gene involvement was detected in glioma and medulloblastoma. The gene discussed is PIK3CA; the disease is central nervous system cancer.