[12] NMR data confirm that the CFC domain has a C1-C4, C2-C6, C3-C5 disulfide pattern and show that structures are rather flexible and globally extended, with three non-canonical anti-parallel strands.

Particularly in cell cultures, it has been shown to act as a signaling molecule with the capabilities of a growth factor, and in co-culture assays, it has displayed the property of a co-ligand to Nodal.

EGF-CFC proteins’ composition as a receptor complex is further solidified by the GPI linkage, making the cell membrane connection able to regulate growth factor signaling of Nodal.

[5] High concentrations of Cripto are found in both the trophoblast and inner cell mass, along the primitive streak as the second epithelial-mesenchymal transformation event occurs to form the mesoderm, and in the myocardium of the developing heart.

Though no specific defect has been formally associated with mutations in Cripto, in vitro studies that disrupt gene function at various times during development have provided glimpses of possible malformations.

[5] Furthermore, the cryptic protein is highly over-expressed in many tumors [11] such as colorectal, gastric, breast, and pancreatic cancers in homosapiens.