PTBP1 and glioblastoma: A robust correlation between SF3B1 expression and the most critical oncogenic spliceosome components [SRSF3/RBM22/PTPB1/RBM3 [23]] was also found in GBM (CGGA- and Rembrandt-datasets), but not in the non-tumor samples (with the exception of PTBP1; Rembrandt-datasets)(Fig. 1m).