CELF2 and bladder transitional cell carcinoma: First, we investigated the differentially expressed SFs in BLCA, and we distinguished eight differential SFs: CELF2, MBNL1, NOVA1, PTBP2, KHDRBS2, ELAVL2, ELAVL3, and ELAVL4. Of these, ELAV2, ELAVL3, and ELAVL4 were upregulated in BLCA, and CELF2, MBNL1, NOVA1, PTBP2, and KHDRBS2 were downregulated (Figure 6A).