Definition of the absolute number of CD34⁺cells.

(A) The percentage CD34⁺ cells in BM (♦), fetal liver (▪), and spleen (▵) was independent of gestational age. Data plotted are derived only from fetuses of which all 3 tissues (BM, liver, and spleen) were available for analysis. (B) Absolute numbers of CD34⁺ cells in BM (♦), human fetal liver (▪), or spleen (▵). (C) Total absolute numbers of CD34⁺cells per fetus are given as measured in liver plus BM plus spleen.