SLBP and hepatocellular carcinoma: The complex containing mH2a/2m-3′B pre-mRNA, SLBP and the in vitro assembled core U7 snRNP bound to 139N FLASH was immobilized on streptavidin (SA) beads and incubated on ice with either a buffer, as a control, or a mouse nuclear extract to recruit missing polyadenylation factors of the HCC, hence reconstituting a semi-recombinant holo U7 snRNP.