AUTHOR=Glossmann Hartmut H. , Lutz Oliver M. D. TITLE=Commentary: Lactate-Induced Glucose Output Is Unchanged by Metformin at a Therapeutic Concentration—A Mass Spectrometry Imaging Study of the Perfused Rat Liver JOURNAL=Frontiers in Pharmacology VOLUME=10 YEAR=2019 URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2019.00090 DOI=10.3389/fphar.2019.00090 ISSN=1663-9812