SULF1 and gastric cancer: Network analysis of the differentially expressed proteins in the intestinal subtype showed increased expression of proteins with an oncogenic role (SULF1, HGF, SPARC, SERPINH1, IGFBP7) and decreased expression of proteins with a tumor suppressive function (AKR1B10, GKN1, TFF2, ADH1C, ADHFE1, ADH7, REG3A, LIPF, ATP4A, ATP4B, PGC) in gastric cancer.