Retraction notice to "A novel circular RNA circ-ZNF652 promotes hepatocellular carcinoma metastasis through inducing snail-mediated epithelial-mesenchymal transition by sponging miR-203/miR-502-5p" [YBBRC 513(4) (2019) 812-819]

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). The authors claim that other members of their lab attempted to repeat the experiments in this study several times and found that the activation ability of snail on circ-znf652 was significantly lower than reported, indicating that this regulation loop does not exist. The authors' incorrect experimental method and lack of reasonable control, coupled with the lack of experimental experience of the first author, led to the mistakes and mean the results cannot be relied upon. In order not to mislead other scientists, they requested to retract their manuscript. The Editor-in-Chief has approved this retraction. The authors apologise to the readership of the journal for these errors.