NGFR and glioblastoma: Our data demonstrated that 85% of GBM specimens (17/20) express p75NTR, that the p75NTR-positive glioma cells in the original patient tumor cell population were more migratory [15], and that 24- and 19-kDa p75NTR-positive fragments are present in p75NTR-positive primary Grade III and GBM patient specimens (Figure 1).