Differential effects of the anticoagulant and signaling properties of endogenous APC on the number of B16F10 pulmonary tumor foci in C57Bl/6 mice. (A) Mice were treated intraperitoneally with 200 μg of an antibody that blocks both anticoagulant and signaling properties of APC (MPC1609; ■), an antibody that only blocks the anticoagulant activity of APC (MAPC1591; ▩), or a control antibody (MCO1716; □) at 30 minutes before the administration of 3.5 × 105 B16F10 melanoma cells into the lateral tail vein. Antibody administration was repeated at 48 and 96 hours after cancer cell inoculation. Mice were killed at 14 days after cancer cell inoculation, and the number of tumor foci at the surface of the lungs was determined (A). Error bars represent means ± SEMs (n = 6-8), ***P < .001. (B) Representative lungs of mice treated with MCO1716, MPC1609, and MAPC1591 antibodies, respectively. Dark dots in the lungs represent melanoma tumors.