All in all, we found four key differentially expressed miRNAs including hsa‐miR‐139‐5p, hsa‐miR‐145‐3p, hsa‐miR‐145‐5p and hsa‐miR‐490‐3p, four DEGs (ADAM12, ACAN, HOXC11 and MMP11) and three related signaling pathways (calcium signaling pathway, bile secretion and gastric acid secretion) in STAD, which provide a novel field for understanding the pathological mechanism of STAD. The gene discussed is ACAN; the disease is gastric adenocarcinoma.