Immunohistochemical analysis of Ki-67 expression in tumor tissues revealed the following percentages of positively stained cells: 16.34 ± 0.9 for the U251 group, 16.29 ± 1.17 for the U251/NC group, 11.15 ± 1.47 for the U251/PEG3-FTH1 group, and 6.47 ± 0.56 for the U251/PEG3-bFGF2 5′UTR-FTH1-WPRE group (Figure 6B). The gene discussed is MKI67; the disease is neoplasm.