Here, in an attempt to identify the miRNAs that regulate GC progression and metastasis, we discovered the under-expression of miR-4521 in advanced GC and its key role in inhibiting GC metastasis through the direct regulation of IGF2 and FOXM1, and the inactivation of AKT/GSK3β/Snai1 signaling. This evidence concerns the gene GSK3B and gastric cancer.