It's published in Nature though, so it is peer-reviewed.
To quote from Wikipedia:
"The papers that have been published in this journal are internationally acclaimed for maintaining high research standards. Fewer than 8% of submitted papers are accepted for publication."
"As with most other professional scientific journals, papers undergo an initial screening by the editor, followed by peer review (in which other scientists, chosen by the editor for expertise with the subject matter but who have no connection to the research under review, will read and critique articles), before publication. In the case of Nature, they are only sent for review if it is decided that they deal with a topical subject and are sufficiently ground-breaking in that particular field. As a consequence, the majority of submitted papers are rejected without review."