This study investigates the molecular mechanisms by which superparamagnetic iron oxide nanoparticles (SPIONs) loaded with the WSGC peptide (WSGC@FA@PEG/PEI‐SPIONs)—a 40‐amino acid polypeptide derived from apoC‐III—modulate chemotherapy resistance in gastric adenocarcinoma (GA). Here, APOC3 is linked to gastric adenocarcinoma.