Maximum likelihood gene network of type II VGPC toxin/Kunitz protease inhibitor genes. Previously characterized protease inhibitors (green) and type II VGPC toxins (blue) are highlighted. Newly-identified candidate toxins are in bold. The transcriptome source is indicated (acrorhagi from A: aggressive or NA: non-aggressive polyps). Labels at the terminal tips indicate GenBank accession number and species identity. For full species names refer to S. Table 2. Bootstrap support values greater than 50 are shown.