CCL22 and neoplasm: Regarding its molecular mechanism, circ-0039569 binds competitively to miR-34a-5p, which in turn induces an increase in the expression levels of the CCL22 gene, which plays a relevant role in tumor immunity, specifically by recruiting regulatory T cells (Tregs) to the tumor, and by promoting the formation of dendritic cells-treg (Röhrle et al., 2020).