Intraperitoneal (i.p.)injection tends to be employed for rodents while intravenous (i.v.)injection used for larger animals, because i.p. is easier than i.v. in rodents while i.v. has the merit of direct injection of STZ without loss of STZ in comparison with i.p. Therefore i.v. injection can induce diabetes at a lower dose of i.p. because more time is required to absorb STZ with i.p., and some of the STZ is inactivated before absorption. The gene discussed is ST3GAL4; the disease is diabetes mellitus.