This family consists of the huwentoxin-II (HWTX-II) family of toxins secreted by spiders. These toxins are found in venom that secreted from the bird spider Selenocosmia huwena Wang. The HWTX-II adopts a novel scaffold different from the ICK motif that is found in other huwentoxins. HWTX-II consists of 37 amino acids residues including six cysteines involved in three disulfide bridges [1].

1: An overview of peptide toxins from the venom of the Chinese bird spider Selenocosmia huwena Wang [=Ornithoctonus huwena (Wang)]. Liang S; Toxicon 2004;43:575-585. PMID:15066414