CstF64 plays an unclear role in processing of histone pre-mRNAs but it may be under-represented relative to the other subunits of endogenous HCC (15,34), resulting in a reduced processing activity of the purified semi-recombinant holo U7 snRNP in the absence of SLBP. This evidence concerns the gene CSTF2 and hepatocellular carcinoma.