In addition to participating in M2 polarization and interacting with macrophages, circRNAs mediate tumor immune surveillance (135, 136), regulate immune escape via PD-L1 (137–140), regulate natural killer cells’ cytotoxicity (141–143), and regulate neutrophils, myeloid-derived suppressor cells, and cancer-associated fibroblast (144). This evidence concerns the gene CD274 and neoplasm.