Among all the signal pathways that regulate cancer development, the LncRNAs-miRNAs-mRNAs competing endogenous networks are closely associated with the pathogenesis of GC (3–6), and this study, for the first time, identified a novel LncRNA MIR503HG/miR-224-5p/TUSC3 signaling cascade that regulated unfolded protein response (UPR) to hamper the development of GC. Here, TUSC3 is linked to gastric cancer.