Consistent with data from GBM cell lines, the TS543 cultures were exquisitely sensitive to PKC inhibitors, while the TS565 cultures were relatively insensitive (Extra sum of squares F-test, P=4.657.10-6) (Figure 5F). Taken together these data suggest that PKC may represent a potential therapeutic target in GBMs in which the NF1 gene is intact and the protein is destabilized.