 Citation patterns are also known to be affected by unethical behavior of both the authors and journal staff.Such behavior is called impact factor boosting, and was reported to involve even the top-tier journals.Specifically the high-ranking journals of medical science, including "The Lancet", "JAMA" and "The New England Journal of Medicine", are thought to be associated with such behavior, with up to 30% of citations to these journals being generated by commissioned opinion articles.