ERBB2 and neoplasm: After administration to HER2+ tumor-bearing mice, anti-HER2 engineered macrophage biomimetic photothermal nanoparticles (GEM@PLGA@HM) escaped the clearance of the macrophage system and actively targeted HER2-expressing tumor cells, resulting in increased accumulation of GEM@PLGA@HM in the tumor with minimal systemic toxicity.