• Our article on quantum encryption incorrectly identified Shuang Wang as the leader of the research group (20 September, p 12). The leader is Zheng-Fu Han.
• Guilty as charged: our article on mitochondria contained two errors (20 September, p 42). Hemes are not proteins but cofactors, and not all free radicals carry a charge.
• Contrary to the claim in our article on dolphin intelligence, cetaceans do not currently have personhood status in any country (27 September, p 46).
