AUTHOR=Yang Cong-wen , Chen Ru-dong , Zhu Qing-run , Han Shi-jie , Kuang Ming-jie TITLE=Corrigendum: Efficacy of umbilical cord mesenchymal stromal cells for COVID-19: a systematic review and meta-analysis JOURNAL=Frontiers in Immunology VOLUME=14 YEAR=2024 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2023.1344990 DOI=10.3389/fimmu.2023.1344990 ISSN=1664-3224