The orphan receptor ALK7 and the Activin receptor ALK4 mediate signaling by Nodal proteins during vertebrate development
Reissmann, E., Jornvall, H., Blokzijl, A., Andersson, O., Chang, C., Minchiotti, G., Persico, M., Ibanez, C. F. (ca) and Brivanlou, A. H. (2001)
Genes & Dev 15, 2010-2022 [PDF]

The orphan receptor serine-threonine kinase ALK7 signals arrest of proliferation and morphological differentiation in a neuronal cell line
Jornvall, H., Blokzijl, A., ten Dijke, P., and Ibanez, C. F. (2001)
J. Biol. Chem. 276, 5140-5146. [PDF]

A novel type I serine-threonine kinase receptor predominantly expressed in the adult central nervous system
Ryden, R., Imamura, T., Jornvall, H., Neveu, I., Trupp, M., Belluardo, N., Okadome, T., ten Dijke, P., and Ibanez, C. F. (1996)
J. Biol. Chem. 271, 30603-30609 [PDF]