EGFR and cancer: Polydopamine (PDA)-coated MNPs functionalized with polyethyleneimine (PEI), for instance, were proven to efficiently deliver genetic materials and induce the expression of EGFR targeting chimeric antigen receptors (EGFR-CARs) on the NK cell surface, which improved the cells’ anti-cancer cytotoxic effect both in vitro and in vivo [86].