Simultaneous abrogation of core signalling pathways in glioblastomas, as recently reported for primary tumours [25], [26], are in evidence in both these cell lines, with further disruption to the p53 pathway (through point mutations of TP53 in both lines), and the RTK/PI3K/AKT pathway via NF1 deletion in SF188 and PIK3CA copy number gain in KNS42. This evidence concerns the gene PIK3CA and glioblastoma.