Ligand gated cation channels of the AMPA/GLuA subtype interact with a family of proteins termed transmembrane AMPA-receptor regulatory proteins (TARPs). These proteins regulate the surface expression and the biophysical properties of GluAs.
A second protein family of 4 members referred to as cornichon 1-4 or CNIH 1-4 has been attributed similar properties in mammals. However it is still under discussion whether these proteins serve as chaperones, involved in the trafficking of EGFR ligands from the ER to Golgi like their homologes in yeast and Drosophila, or as GluA auxilliary subunits. For CNIH 3 three isoforms have been described.