Fig. 3

A summary of the regulation network of Ids in heart development is shown. In cardiogenesis, Ids play an important role by regulating the transcription and expression of a variety of key cardiac factors and these regulatory functions are regulated by various signalling pathways and transcription factors. As direct downstream targets of the BMP-Smad signalling pathway, Ids are also regulated by Wnt and IGF signalling pathways. Tbx5 and Nkx2.5, two cardiac transcription factors, also regulate Id to mediate the specification of ventricular myocytes into the ventricular conduction system lineage