MUC5AC and Patent ductus arteriosus: The small difference in EC-MUC5AC detection rates between the NR (63%) and OR (56%) groups, despite having larger differences in intracellular MUC5AC expression (mean H-score, OR vs. NR = 113 vs. 153) for patients who had curative resection without progression or distant metastasis, highlights the clinical significance of EC-MUC5AC in PDA, as demonstrated in preclinical studies [39].