Kinetic analyses of Flk-1, Scl, VE-cadherin, CD45, and Ter-119 expression. In vitro–differentiated Scl^+/hCD4 ES cells during EB and OP9 differentiation (from day 2.75 to day 7) were subjected to FACS analyses for Flk-1, hCD4, VE-cadherin (A) and CD45 and Ter119 (B) expression. Numbers in a given box indicate the percentage of each population. In each 2-row group of scatterplots, the top row shows EB differentiation while the bottom row shows OP9 differentiation.