This family consists of the I-superfamily of conotoxins. This is a new class of peptides in the venom of some Conus species. These toxins are characterised by four disulfide bridges and inhibit of modify ion channels of nerve cells. The I-superfamily conotoxins is found in five or six major clades of cone snails and could possible be found in many more species [1].

1: Novel conopeptides of the I-superfamily occur in several clades of cone snails. Kauferstein S, Huys I, Kuch U, Melaun C, Tytgat J, Mebs D; Toxicon 2004;44:539-548. PMID:15450929