Immunogen sequence: AKKLDKENLS DERASGQSCT LPKRSDSELK DEKPKRPEDE SGRDYRERER EYERDQERIL RERERLKRQE EERRRQKERY EKEKTFKRKE EEMKKEKDTL RDKGKKAEST ESIGSSEKTE KKEEVVKRDR IRNKDR. UPF3B is part of a post-splicing multiprotein complex involved in both mRNA nuclear