Furthermore, zero-valent iron nanoparticles (ZVI-NP), the ferroptosis inducer, induced cancer-specific cytotoxicity reducing the number of Tregs and decreasing the expression of PD-L1 on tumor cells and PD-1/CTLA4 on CD8+ T-cells, exerting an anti-tumor immune effect (86). This evidence concerns the gene CTLA4 and neoplasm.