In another innovative approach, Zhao et al. (2018) addressed the challenges of poor tumor accumulation and rapid clearance associated with traditional nanodrug delivery systems by developing macrophage membrane (M)-camouflaged, quercetin-loaded hollow bismuth selenide nanoparticles (M@BS-QE NPs).80 This biomimetic surface engineering endowed the nanoparticles with immune evasion capabilities, extended circulation time, and enhanced tumor homing, primarily due to the presence of C–C chemokine ligand 2 (CCL2)-mediated recruitment and active targeting mechanisms. The gene discussed is CCL2; the disease is neoplasm.