In the October 22 issue of Nature, the Tsai lab reports the "product template" (PT) domain that is crucial for aflatoxin formation in the molds. Prior to this study, no information is available as to how the moldy fungi can precisely fold a carbon chain to end up with the complicate chemical structure crucial for poisoning our body and cause cancer. The aflatoxin-PT study revealed, for the first time, how PT would fold an incoming linear carbon chain called polyketide to form two aflatoxin rings in an amazing feat of origami, and how this mechanism can also be applied to other moldy toxins.