Then, the principles of ceRNA network mechanisms (12, 13) convince us to investigate the downstream targets of LncRNA MIR503HG, and we successfully screened out that LncRNA MIR503HG sponged miR-224-5p to upregulate TUSC3 in GC cells, and both miR-224-5p overexpression and TUSC3 ablation abrogated the tumor-inhibiting effects of LncRNA MIR503HG on GC, implying that LncRNA MIR503HG regulated the miR-224-5p/TUSC3 axis to hamper GC progression. This evidence concerns the gene TUSC3 and gastric cancer.