Antitumor activity of P38B against CHO/dPDPN and CHO-K1. (A) Tumor volume of CHO/dPDPN xenografts. CHO/ dPDPN cells were injected subcutaneously into female nude mice. The indicated antibodies (100 μg/day; 5 mg/kg) were administered intraperitoneally on days 1, 8, and 15 after cell inoculation. The tumor volume was measured at the indicated time points. The values are presented as mean ± SEM. (B) CHO-K1 cells were injected subcutaneously into female nude mice. The indicated antibodies (100 μg/day; 5 mg/kg) were administered intraperitoneally, and canine mononuclear cells were injected around the tumors on day 1, day 8, and day 15. The tumor volume was measured at the indicated time points. The values are presented as mean ± SEM. An asterisk indicates statistical significance (* P < 0.05, Tukey-Kramer's test). n.s.: not significant.