TLR9 and central nervous system cancer: Although there is contradictory results for the expression of TLR9 in the GL261 cells between Grauer's result[13] and Meng's result[17], both of them confirmed that the prolonged survival seen in their study was not due to the expression of TLR9 expression in glioma cells, but rather due to increased apoptosis of GL261 cells in vivo and enhanced modulation of the local CNS immune response.