AUTHOR=Wu Guo-Liang , Liu Yao-Zhong , Zhang Lei TITLE=Editorial: Mendelian Randomization: Approach and Applications JOURNAL=Frontiers in Genetics VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2021.752146 DOI=10.3389/fgene.2021.752146 ISSN=1664-8021