TF and central nervous system cancer: The survival curves of U87 glioma-bearing mice at different times after treatment with saline, DOX solution, LPs or Tf-LPs are presented in Figure 8A. The survival time of mice treated with Tf-LPs (25 days) was longer than that of mice treated with saline (20 days), free DOX (22 days) and LPs (24 days), which may be attributed to the presence of cell-penetrating peptide and Tf [20].