PIK3CA and central nervous system cancer: The targeted sequencing panel was designed to target glioma related genes (IDH1/2, TP53, ATRX, CIC, FUBP1, EGFR, PTEN, CDKN2A/B, NF1, PIK3CA/R1, BRAF, hTERT promoter) and included probes to determine copy number status of chromosomes 1p/19q, CDKN2A/B, PTEN, and EGFR. A total of 108 samples (57 FFPE and 51 fresh frozen) were collected and DNA extracted.