Effect of anti-p34-58 and anti-PF4 (p34-58)⁻ antibodies in presence of PF4 or p34-58 on the formation of and CFU-MK from total cells of bone marrow. Values are expressed as the mean ± SEM of triplicate determination obtained from three independent experiments. *P < .01 as compared with control value determined by the Student's t-test. One hundred percent (100%) corresponds to 91 CFU-MK colonies/mL of control cultures.