PKM and gastric cancer: In the in vitro model of CAFs differentiated from mesenchymal stem cells (MSCs) by gastric cancer-derived exosomes, we found that the main protein components of gastric cancer-derived exosomes are metabolism-related proteins, especially glycolytic enzymes, M2 pyruvate kinase (PKM2), lactate dehydrogenase A (LDHA), and phosphofructokinase P (PFKP), while PKM2 was frequently upregulated at the mRNA and protein levels in CAFs differentiated from MSCs.