Fig. 3. BMP4 and VEGF are critical for the generation of SCL-expressing cells. (A) Scl^+/CD4 ES cells were in vitro differentiated in serum (FCS) or serum-free conditions (SR) in the presence of factors shown. Day 5 EB cells were subjected to FACS analysis for FLK1 and CD4 expression. Numbers in a given box indicate the percentage of cells that are FLK1⁺CD4^– (lower right), FLK1⁺CD4⁺ (upper right), or FLK1^–CD4⁺ (upper left). (B) Statistical analyses of CD4⁺ cells developing in BMP4 (day 5-6 and 7) or BMP4+VEGF (day 5-6). (C) Both VEGF₁₂₁ and VEGF₁₆₅ are effective in SCL-expressing cell induction. Day 7 Scl^+/CD4 EB cells, differentiated in serum-free conditions in the presence of BMP4, BMP4+VEGF₁₂₁, BMP4+VEGF₁₆₅ or BMP4+VEGF₁₂₁+VEGF₁₆₅ were subjected to FACS analysis for FLK1 and CD4 expression. Numbers in a given box indicate the percentage of cells that are FLK1⁺CD4^– (lower right), FLK1⁺CD4⁺ (upper right), or FLK1^–CD4⁺ (upper left).