DDX21 and urinary bladder carcinoma: Moreover, eukaryotic translation initiation factor 3 subunit A (EIF3A), DDX21, SDE2, transportin 1 (TNPO1), and ring finger protein 40 (RNF40) are thought to mediate multiple alternative splicing events in bladder cancer, implying their essential roles in the development and progression of this disease (114).