VCP and liver cancer: However, PARylation and ubiquitylation exert opposite effects on DDB2; they modify K1-7 located within the first 40 N-terminal amino acid residues as follows: (I) PARylation results in the stabilization of the protein and promotes the recruitment of ALC1 (Amplified in liver cancer 1) chromatin remodeler; (II) K48-linked polyubiquitylation leads to its VCP/p97 (Valosin-containing protein)-mediated proteasomal degradation [24,25] (Figure 1A,C).