OL Oncology Letters 1792-1074 1792-1082 D.A. Spandidos 10.3892/ol.2026.15802 OL-32-4-15802 Expression of Concern [Expression of Concern] Circular RNA ATAD1 is upregulated in acute myeloid leukemia and promotes cancer cell proliferation by downregulating miR-34b via promoter methylation WuYarong GaoBingjun QiXiaolei BaiLiyun LiBixin BaoHongjing WuXi WuXiaoyun ZhaoYuxia 102026 05082026 32 4 447 Copyright: © Wu et al. 2026 This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited.

Oncol Lett 22: 799, 2021; DOI: 10.3892/ol.2021.13060

Following the publication of the above paper, it has been drawn to the Editor's attention by a concerned reader that, regarding the cellular images of the Kasumi-6 cells shown in Fig. 4D on p. 7, the ‘circ-ATAD1’ and ‘circ-ATAD1+miR-34b’ data panels are apparently matching, suggesting that this figure has been assembled incorrectly

The authors have been contacted by the Editorial Office to offer an explanation for this apparent anomaly in the presentation of the data in this paper, and we are awaiting their response. Owing to the fact that the Editorial Office has been made aware of this potential issue surrounding the scientific integrity of this paper, we are issuing an Expression of Concern to notify readers of this potential problem while the Editorial Office continues to investigate this matter further.