PDCD1 and gastric cancer: The translation of FZD2’s dual roles into clinical practice requires addressing three core challenges: determining the molecular basis for its ligand specificity, validating bromodomain inhibitors as synergistic agents with PD-1 blockade in hypermutated tumors, and establishing the FZD2-TMB/MSI signature as a predictive biomarker for Wnt-targeted therapies in advanced gastric cancer.