The News Feature ‘The impenetrable proof’ (Nature 526, 178–181; 2015) incorrectly stated that Shinichi Mochizuki estimated that it would take an expert 500 hours to understand his proof. In fact, this was Ivan Fesenko’s estimate. The story also stated that Fesenko warned Mochizuki against speaking to the press, but this was not part of their discussion.

The News Feature ‘Brain, meet gut’ (Nature 526, 312–314; 2015) incorrectly stated that the US Office of Naval Research agreed to commit US$52 million into gut–brain research. In fact, the figure is closer to $14.5 million over the next 6–7 years.

The Editorial ‘The worm returns’ (Nature 526, 294; 2015) gave the wrong date for the landmark ‘The mind of the worm’ paper. The paper was published in 1986, not 1984.