The histone pre-mRNA 3′-end-processing complex contains a seven subunit Sm ring bound to U7 snRNA; subunits Lsm10, Lsm11, FLASH, and SLBP; and the HCC subcomplex that is composed of the same subunits as mCF, including endonuclease CPSF73 (41, 89). Here, CPSF3 is linked to hepatocellular carcinoma.