A special type of small sulfur-rich protein, metallothioneins, have an extraordinary capability for binding heavy metals. An international team of scientists has now discovered that the marine common periwinkle, which is widely considered a delicacy, contains the largest version of the protein found yet, with one additional cadmium-binding domain and a one-third higher detoxification capacity. As they report in the journal Angewandte Chemie, this feature may help the snail survive in heavy-metal-polluted environments.