,231,232,233,234,235,236,237 Notably, the development of a dual-targeting drug delivery system named Pep-21, combining a PD-L1-binding peptide with anti-miR-21 inhibitor, demonstrated the efficient binding to tumor cells and macrophages inducing decrease of miR-21 levels, tumor cell migration, and a macrophage polarization toward M1-phenotype and finally suppression of B16 melanoma progression.236. This evidence concerns the gene CD274 and neoplasm.