Recovery in c-Myb^Plt4/+ and p300^Plt6/+ mice after 5-FU–induced thrombocytopenia. Platelet count (top panel), white blood cell count (middle panel), and hematocrit (bottom panel) in (A) c-Myb^Plt4/+ (squares) or wild-type (c-Myb^+/+, circles) mice, and (B) p300^Plt6/+ (triangles) or wild-type (p300^+/+, circles) mice were determined after administration of 5-FU. Data points represent the mean ± SD from separate cohorts of mice analyzed at the times indicated. *P < .05 in Student t test for comparison of data from c-Myb^Plt4/+ mice with that of c-Myb^+/+ controls, or p300^Plt6/+ mice with that of p300^+/+ controls. n = 2 (closed symbols) or 3 to 12 mice (open symbols) per point.