In addition, an adenoviral vector with the hON-522E-promoter–driven herpes simplex virus thymidine kinase gene (Ad-522E-TK) was highly effective against the growth of androgen-independent human prostate cancer PC3M and bone stromal cell line in vitro and in pre-established PC3M tumors in vivo upon addition of the prodrug ganciclovir. The gene discussed is TKT; the disease is prostate cancer.