PDE4A and gastric adenocarcinoma: RGS2, GNAI2, ANXA5, MARCKS, CD36, NRP1, and PDE4A were the prognostic factors of STAD, among which, GNAI2 and PDE4A were protective indicators, while RGS2, ANXA5, MARCKS, CD36 and NRP1 were risk indicators (Fig. 3D).