Editorial Expression of Concern: Co-encapsulation of HNF4α overexpressing UMSCs and human primary hepatocytes ameliorates mouse acute liver failure

• An Editorial Expression of Concern has been issued regarding the reporting of animal ethics approval in the original article. • The approval number cited in the article (SYXK 2008 0050) was found to be a general facility license, not a study-specific ethics approval. • The authors clarified that separate ethical approval was obtained for the study, but the reporting was inadequate. • Readers are advised to interpret the animal ethics approval information with caution.