Here, we fully elucidated the functions of RUNX3/circMETTL3/miR-107/PER3 axis in CRC: RUNX3 level is diminished due to the hypermethylation in CRC, leading to reduced circMETTL3 expression in that RUNX3 acts to activate circMETTL3 transcription. Here, RUNX3 is linked to colorectal carcinoma.