AUTHOR=Papadopoulos Konstantinos I. , Turajane Thana TITLE=Commentary: Autologous Peripheral Blood Stem Cells (PBSC) are Safe and Effective in Knee Osteoarthritis JOURNAL=Frontiers in Pharmacology VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2021.652738 DOI=10.3389/fphar.2021.652738 ISSN=1663-9812