Metformin's antitumor activity in vitro and in vivo may also be associated with inhibition of the insulin/IGF-1 pathway via AMPK activation by inactivation of breast CD44+/CD24 CSCs and the EMT phenotype, or even with inhibiting cellular proliferation, clonogenic potential, migration/invasion, and CSC self-renewal capacity in gemcitabine-resistant pancreatic cancer cells [162]. Here, CD44 is linked to pancreatic neoplasm.