Antitumor effects of mAb A4 and mAb A4M. (A) MAb A4 injected i.p. led to inhibition of B16F10-Nex2 subcutaneous tumor growth (black circles, n = 5). Controls, animals injected i.p. with irrelevant antibody (white circles, n = 5). (B) Survival record of both groups treated with mAb A4 and the control group (P < .001). (C) Effect of the mAb A4 and mAb A4M-treatment on experimental lung metastases showing a significant decrease in their number with both mAbs (P = .05 and P < .05, respectively). (D) Representative lungs from control and mAb-treated animals after 25 days of intravenous tumor challenge. Control, animals treated with irrelevant antibody at the same concentration.