ALB and neoplasm: Anionic agents of high-avidity (HSA) and high PEG density (PHSA; ca. 35% of the surface), which exhibited modest or poor efficiencies comparable to those of fully PEGylated species in vitro, rather demonstrated superb tumor-targeting efficiency in vivo, which is presumably due to their low off-target uptake, prolonged blood circulation, and/or fast extravasation process relative to those of other nano-sized agents.