PTBP1 and glioblastoma: Thus, the oncogenic splicing program of glioblastomas is a result of both overexpression of PTBP1 and the downregulation of RBFOX RBPs compared to healthy brain tissues (Fig. 6i), in which the splicing activities of these RBPs are correspondingly high and low relative to many other tissues55 (Supplementary Fig. S13).