As shown in Fig. 5, injection of 100 μg and 1 μg of tk-JCPyV VLP-SPBs combined with GCV significantly inhibited the growth of tumors from only HT-1376 bladder cancer cells but not those of A549 lung cancer cells (Fig. 5A, tk-JCPyV VLP-SPB/GCV, the fourth and fifth panels, respectively). Here, TKT is linked to urinary bladder cancer.