As Biology Open (BiO) completes its first full year of publication, I would like to take this opportunity to thank all of our reviewers for their hard work (a full list of our reviewers can be found below). All these people have given us their valuable time for free and BiO could not exist without them; we are very grateful for all their efforts.Peer review is a precious thing. Without it, Open Access journals such as BiO could end up being little more than ‘vanity’ publishers, publishing more or less any paper because to do so increases profits. Critics of author-pays Open Access are right to point out that such journals exist, but they are wrong to suggest that we will all end up drowning in a quagmire of irrelevant and irreproducible data as a result. Scientists are not fools and any journal that adopted this policy would rapidly lose credibility. For the record, 250 papers were submitted to BiO in 2012; so far, 137 have been accepted and 79 rejected (a rejection rate of ∼40%).Indeed, I would argue that peer review at BiO might actually be more effective than it is at some of the very high-impact factor journals. Our reviewers are asked to focus only on whether the conclusions of a paper are justified by the data presented. I have been amazed at how good our reviewers are at spotting any important deficiencies in a paper and suggesting how these can be addressed – often simply by performing an essential control or by toning down a particular conclusion. It is very rare that we accept a paper at BiO without asking for some changes or additional work to be done, but this is always aimed at ensuring that the conclusions are properly backed up by the data.Several of our authors have commented on how refreshing it is to be able to write a paper honestly and openly, without having to stretch and/or omit data to ensure that an important and definitive conclusion is reached. As I have discussed before (Raff, 2012), given the extreme pressures on scientists to publish in journals with high impact factors, it is perhaps no surprise to learn that other scientists often find the data published in these journals difficult to reproduce (Begley and Ellis, 2012; Mullard, 2011). Thanks to our reviewers, I am very hopeful that this will be less of a problem for papers published in BiO.