REG4 and gastric cancer: Kaplan‐Meier survival analysis (Figure S4M) revealed that the marker genes PLCG2 (C1, OS, p = 0.026), LIPF (C2, OS, p = 0.1), REG4 (C3, OS, p = 0.065), and GAST (C4, OS, p = 0.021) were closely related to the prognosis of patients with GC.