Although demonstrating specific in vitro targeting of HER2-expressing cancer cells, these nanocarriers were significantly hampered by their large hydrodynamic diameter (HD) (>20 nm), which exceeded the renal clearance cutoff, leading to rapid hepatic clearance and/or reticuloendothelial system (RES) uptake, severe aggregation, as well as low cumulative tumor uptake. Here, ERBB2 is linked to cancer.