CDK1 and nasopharyngeal carcinoma: What makes more sense is that metformin interrupts the AMPKɑ/ p-Drp1 Ser637 signaling pathway or cucurbitacin E targets the cyclinB1-Cdk1/p-Drp1 (Ser616) axis repressing mitochondrial fission.101 This discovery supports the mitochondrial dynamics markers Drp1 Ser616 and Ser637 as crucial targets for NPC in the future.