GLIPR1 and glioblastoma: Moreover, as presented in Fig. 1B and 1C, RTVP-1 expression in GBM was positively correlated with the mesenchymal metagene score (Pearson correlation 0.78, P < 0.0001) and negatively correlated with the proneural metagene score (Pearson correlation −0.583, P < 0.0001); both were generated from the recently reported mesenchymal and proneural genes lists [10].