ARRB1 and cancer: To further clarify the pathological importance of AEP/tDDX3X–mediated ARRB1-Δexon 13 splicing in cancer, we performed Western blotting and verified the significantly higher protein levels of AEP and tDDX3X in HGG and recurrent glioma (RecG) than in normal tissues and LGG (Figure 8, A–C and Supplemental Figure 12A).