MTHFD2 and gastric cancer: Among the affected miRNAs, miR-22 was identified to remarkably suppress gastric cancer (GC) cell proliferation, arrest G1–S cell cycle transition, and induce cell apoptosis by targeting MeCP2, MTHFD2, and MTHFR. Understanding GC metabolism characteristics is the key to developing novel therapies that target GC metabolic pathways.