EDC4 (enhancer of mRNA decapping 4) is a large scaffold protein that orchestrates mRNA decay through multiple interconnected mechanisms. Functionally, EDC4 serves as a central hub organizing the mRNA decapping complex by promoting assembly between DCP1A and DCP2, while enhancing DCP2 catalytic activity 1. EDC4 also recruits the 5'-3' exonuclease XRN1, and the EDC4-XRN1 interaction critically regulates P-body dynamics to coordinate decapping with downstream mRNA degradation 2. The C-terminal domain (residues 1266-1401) drives phase separation and P-body formation through self-association 3. Beyond mRNA decay, EDC4 has unexpected roles in DNA repair and disease pathology. EDC4 functions as a member of the BRCA1-BRIP1-TOPBP1 complex, stimulating end resection at double-strand breaks; EDC4 deficiency phenocopies BRCA1 loss and increases sensitivity to PARP inhibitors 4. In Parkinson's disease, pathological alpha-synuclein accumulation aberrantly interacts with EDC4, disrupting normal decapping-module interactions and dysregulating mRNA decay in disease-relevant pathways 1. EDC4 regulation involves mTORC1-mediated phosphorylation affecting its protein expression and complex interactions 5. Additionally, viral pathogens exploit EDC4; Ebola virus VP35 binds EDC4 to hijack the decapping complex for viral RNA synthesis 6. These findings establish EDC4 as a multifunctional scaffold integrating mRNA metabolism with genome maintenance and disease pathogenesis.