Mild reduction in platelet counts of CD47^-/- mice. Platelet counts in 8- to 12-week-old CD47^+/+, CD47^+/-, and CD47^-/- (A) female (n = 10, 11, and 13, respectively) or (B) male (n = 9, 2, and 12, respectively) C57BL /6 mice. Data are means ± SEMs. ^*P < .05 and ^**P < .01, using Student t test for unpaired samples.