Overexpression of the Lycat transgene specifically increased hematopoietic and endothelial gene expression in EBs using a microarray analysis. We identified differentially expressed genes between VC and FC5 ES cell-derived D4 EBs using SmartArray (CapitalBio, Beijing, China) chips containing about 25 000 mouse genes. The top 200 affected genes were shown to be up- and down-regulated from 2- to 37-fold (averaged from 2 independent experiments) in FC5 EBs, of which 65 genes are related to hemangioblastic, hematopoietic, and endothelial lineages. Thirty-five of these genes and HoxB1 (1.5-fold decrease) were chosen and verified by Q-PCR. These genes were clustered into mesoderm/hemangioblast genes (A), endothelial genes (B), hematopoietic genes (C), cardiac genes (D), Hox family genes (E), and pluripotency genes (F). Q-PCR was carried out using SYBR Green, and RNA levels were normalized by GAPDH. Error bars represent standard deviations