The formation of the HDE–U7 duplex with the pre-assembled U7 snRNP/HCC/FLASH (FLASH=FLICE-associated huge protein) complex in the histone locus bodies (HLBs) during the S phase, and its interaction with the N-terminal domain of SYMPK and CPSF100, have been proposed to trigger structural rearrangements within the HCC module needed for the activation of mRNA processing by CPSF73 (19,22–24). This evidence concerns the gene SYMPK and hepatocellular carcinoma.