In vivo–released platelets from infused megakaryocytes. (A) Determined released or infused platelet half-lives. Mean ± 1 SEM are shown. N = 9 for hdPlt infusions. N ≥ 6 for megakaryocyte infusions. (B-C) Fold-difference in the number of human platelets released after infusing megakaryocytes expressed relative to control megakaryocyte infusions corrected for (B) the number of CD41⁺CD42b^High megakaryocytes infused or (C) the number of HPCs initially plated. Mean ± 1 SEM are shown; N = ≥6 per arm. Horizontal lines are the control megakaryocytes value at 1. *P ≤ .05 compared with control by 1-way ANOVA analysis. Plt, hdPlt infusion.