Plasma APC anticoagulant cofactor activity and PS antigen levels. (A) APC cofactor activities. Data are mean ± standard deviation (SD) of Pros1^+/+ (n = 10), Pros1^+/E (n = 10), Pros1^E/E (n = 10), and Pros1^+/− (n = 8) mice. (B) PS antigens. Data are mean ± SD of 5 mice for each genotype. *P < .05 in comparison with Pros1^+/+ mice. ^†P < .001 in comparison with Pros1^+/+ mice, and P < .05 in comparison with Pros1^+/E mice. ^#P < .001 in comparison with Pros1^+/+, Pros1^+/E, and Pros1^E/E mice. The levels measured in Pros1^+/+ mice were defined as 100%.