Cryptic (CFC1) is a member of the epidermal growth factor (EGF)- Cripto, Frl-1, and Cryptic (CFC) family. It contains an EGF-like domain, and is glycosylated on its N-terminal during post-translational modification. Cryptic is identified as a NODAL coreceptor involved in the correct establishment of the left-right axis. It may play a role in mesoderm and/or neural patterning during gastrulation. The unnormal expression of this gene may causes a series of diseases such as HTX2, Transposition of the great arteries dextro-looped 2, and Conotruncal heart malformations.