When circRNAs and miRNAs have binding sites, they can bind competitively, and circRNAs act as sponges, thus affecting miRNA regulation of target genes. The role of circRNA-miRNA-mRNA regulatory networks in various tumours has been extensively reported. In BC, the regulatory network is also involved in many biological processes, such as inhibition of tumorigenesis, invasion and migration. Table 2 lists circRNAs, miRNAs and target mRNAs that inhibit tumours and their roles in the progression of
