To examine the function of METTL14 in GC cells, we directly knocked down METTL14 using two shRNA plasmids (Supplementary Fig. 2a, b) and found that METTL14 knockdown significantly promoted the proliferation, clonogenic and migration abilities of GC cells (Supplementary Fig. 2c-k). This evidence concerns the gene METTL14 and gastric cancer.