AUTHOR=O'Donoghue Patrick , Heinemann Ilka U. , Fan Chenguang TITLE=Editorial: Synthetic Nucleic Acids for Expanding Genetic Codes and Probing Living Cells JOURNAL=Frontiers in Bioengineering and Biotechnology VOLUME=9 YEAR=2021 URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2021.720534 DOI=10.3389/fbioe.2021.720534 ISSN=2296-4185