AUTHOR= Frontiers in Genetics TITLE=Expression of Concern: Enhancement of RNA-directed DNA methylation of a transgene by simultaneously downregulating a ROS1 ortholog using a virus vector in Nicotiana benthamiana JOURNAL=Frontiers in Genetics VOLUME=7 YEAR=2016 URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2016.00202 DOI=10.3389/fgene.2016.00202 ISSN=1664-8021