In order to further explore the role of METTL3 in GC, luciferase-labeled MGC80-3 cells were constructed (MGC80-3-Luc), then METTL3 or shDEK was introduced into MGC80-3-Luc cells with lentivirus and finally, the cells were injected into nude mice via the tail vein, and the growth of lung metastases was monitored by bioluminescence imaging (BLI). The gene discussed is METTL3; the disease is gastric cancer.