As expected, we found that circ-APC could bind directly to TET1 (a well-known demethylase that iteratively oxidizes 5mC to 5hmC) and recruit it to the APC promoter, thereby reducing the methylation level and potentiating the transcription of APC. Thus, circ-APC upregulated APC expression in DLBCL at both the transcriptional and post-transcriptional levels. This evidence concerns the gene TET1 and diffuse large B-cell lymphoma.