EDC4 is a scaffold protein that orchestrates mRNA decapping and decay within processing bodies (P-bodies), membraneless organelles central to mRNA metabolism. It promotes complex formation between the decapping enzymes DCP1A and DCP2, and interacts with the 5'–3' exonuclease XRN1 to coordinate deadenylation-dependent mRNA turnover 1. The EDC4 C-terminal domain (residues 1266–1401) is sufficient to drive P-body assembly through phase separation 2. Beyond mRNA decay, EDC4 has emerged as a multifunctional regulator. It associates with the DNA repair complex BRCA1–BRIP1–TOPBP1 and stimulates homologous recombination by promoting end resection at double-strand breaks 3. In Parkinson's disease, pathological accumulation of alpha-synuclein disrupts physiologic decapping-module interactions at the EDC4 scaffold, altering mRNA decay kinetics in disease-relevant pathways 4. EDC4 also integrates inflammatory signaling through phosphorylation by IκB kinase, which recruits decapping proteins and regulates stability of pro-inflammatory cytokines 5. Clinically, EDC4 dysfunction contributes to cancer susceptibility. Loss-of-function mutations were identified in BRCA1/2-mutation-negative breast cancer cases, and EDC4-deficient cells exhibit hypersensitivity to PARP inhibitors 3. In renal cell carcinoma bone metastasis, circRNA-mediated disruption of the EDC4–DCP1/DCP2 interaction increases IL-11 mRNA stability and activates pro-osteoclastogenic STAT-3 signaling, suggesting potential therapeutic targeting via gene delivery approaches 6.