Twenty-two journals each had 15 or more retracted articles.

1Two authors, H. Zhong and T. Liu, accounted for most of the retractions from Acta Crystallogr E, as did Joachim Boldt for Anesth Analg.2All 49 articles from Gene Express Pattern were retracted due to a publisher error in which an entire issue of journal Mech Dev was accidentally published as Gene Expr Patterns. This journal was not covered in its entirety in Web of Science, so the count of 871 “records since 1980” is from PubMed.317 of 25 J Hazard Mater retractions were authored by Pattium Chiranjeevi.4The count of 532 articles since 1980 is an underestimate since WoS only includes articles for volume 4 onward for this journal, and it is not covered by PubMed. This is a Korean-language journal to which we have no access, so the reason for this large percentage is not known.512 of the 16 retractions for Hear Res were articles accidentally posted online on two different dates (2009 Oct 8 and 2010 Jan 30), indicating two isolated editorial errors.