Previous studies have shown that the deacetylation of proteins is a key regulator of cancer stemness and progression.[55, 56] Since HDAC1 is a well‐known deacetylase, we further evaluated whether the acetylation of c‐Myc could be regulated by HDAC1 and found that the deacetylation level of the K148 site of the c‐Myc sequence was predominantly regulated by HDAC1 and circCFL1. This evidence concerns the gene MYC and cancer.