Effect of G3139 alone or in combination with EP on the growth of M14 tumor cells implanted in mice. (black diamond), untreated; (black square), EP alone; (black triangle),G3139 alone; (asterisk), G3139 and EP. Mice were injected i.v. with G3139 at the dose of 0.2 mg/mouse/day and followed, five minutes later, by the delivery of electric pulses to tumors by means of caliper electrodes. Treatments were repeated for five consecutive days. Mean tumor weights in mg ± s.d. are shown. Arrow indicates the start of treatment. Each experimental group included 8 mice.