Reconstitution with Shp-2 rescues ES cell differentiation and hematopoiesis. (A) ES cell colonies were scored following 48 hours of culture without LIF. The number of differentiated colonies was divided by the total number of colonies to yield percent differentiated colonies. Two independent experiments, cultures plated in duplicate; *P = .009 comparing Shp-2^R1 to Shp-2^Δ and **P = .05 comparing Shp-2^R2 to Shp-2^Δ. (B) EBs were scored for the presence or absence of hemoglobinized cells at day 8 to 10 of differentiation. The number of hemoglobinized EBs was divided by the total number of EBs to yield percent hemoglobinization. Three independent experiments, cultures were plated in duplicate; *P < .0001 comparing Shp-2^R1 to Shp-2^Δ and **P = .06 comparing Shp-2^R2 to Shp-2^Δ. (C) Primitive erythroid (Ery^P) progenitors; 2 independent experiments, cultures plated in duplicate; *P = .04 comparing Shp-2^R1 to Shp-2^Δ. All assays for definitive progenitors were conducted 2 independent times and all cultures were in duplicate. (D) Definitive erythroid (EryD) progenitors; *P = .03 comparing Shp-2^R1 to Shp-2^Δ. (E) Mixed progenitors; *P = .002 comparing Shp-2^R1 to Shp-2^Δ. (F) Granulocyte-macrophage (GM) progenitors; *P < .0001 comparing Shp-2^R1 to Shp-2^Δ. Error bars represent SEM.