To further investigate the effects of the USP3-COL9A3/COL6A5 axis on tumour metastasis in GC in vivo, we established BGC-823 cells stably depleting USP3 by lentiviral transfection, with simultaneous overexpression of COL9A3 or COL6A5. The gene discussed is COL6A5; the disease is gastric cancer.