Johnson et al. (2010) found that the mean tumor volume in FA-PEAs:VHL-treated mice was decreased about 30% compared with that in the control group. Due to the limited expression of folate receptors on healthy cells and overexpression in RCC, FA-PEAs:pVHL complexes could specifically bind to the cell surface via a ligand–receptor incorporating mechanism (Sudimack and Lee, 2000). This evidence concerns the gene VHL and renal cell carcinoma.