Figure 6From: G1 checkpoint establishment in vivo during embryonic liver developmentA proposed model of G1 checkpoint establishment during embryonic liver development. In response to IR damage, G2 cell cycle checkpoint is present in ES cells [8–10] and in E11.5 to E17.5 embryonic liver cells. At E13.5/E15.5 stage, G1 cell cycle checkpoint is established under the regulation of p21-CDK/cyclin E pathway.Back to article page