PTGER3 and gastric cancer: The significant differences were observed between EBVaGC and GS-GC for GDF5 (P < 0.001), and between EBVaGC and GS-GC/CIN-GC for SMAD5 (P < 0.001/P = 0.003) and PTGER3 (P < 0.001/P = 0.021) (Table 2).