TRPC channels form the subfamily of channels in human most closely related to drosophila TRP channels. Structurally, this family shares a number of similar characteristics. At the proximal C-terminus of this sub-family is a TRP box motif containing the invariant EWKFAR sequence and between 3 and 4 ankyrin repeats near the N-terminus. These channels are non-selectively permeable to cations, with a selectivity of calcium over sodium variable among the different members. Many of TRPC channel subunits are able to coassemble.