Fig. 10. A reinforcing transcriptional network for gene activation in the lateral mesoderm dependent on GATA4. In this model, GATA4 expression is activated indirectly by BMP4 (indicated by a dashed arrow) and directly by Forkhead factors, such as FOXF1. BMP4 and FOXF1 reciprocally activate the expression of one another, which further reinforces GATA4 expression. GATA4 then further reinforces the program by activating its own transcription and the transcription of downstream mesodermal genes. Red arrows represent evidence provided in the current study. Black arrows represent evidence provided by previously published studies. Dashed arrows indicate either a direct or indirect activation; solid arrows represent direct activation through direct enhancer binding.