A cover letter is an official letter written by the corresponding author and signed by all authors which introduce the manuscript briefly and states that:
(1) The manuscript is an original work of author. All data, tables, figures, etc. used in the manuscript are prepared originally by authors, otherwise the sources are cited and reprint permission should be attached.
(2) The manuscript has not been and will not be published elsewhere or submitted elsewhere for publication.
(3) Conflict of interest: To prevent the information on potential conflict of interest for authors from being overlooked or misplaced, mention this information in the cover letter.
(4) Ethics of experimentation/Informed consent: The cover letter must include a statement declaring that the study complies with current ethical considerations. Authors reporting experimental studies on human subjects must include a statement of assurance in the Materials and Methods section of the manuscript reading that:
(a) Informed consent was obtained from each patient included in the study
(b) The study protocol conforms to the ethical guidelines of the 1975 Declaration of Helsinki as reflected in a prior approval by the institution's human research committee.
(c) In studies involving animal experimentation, provide assurance that all animals received humane care according to the criteria outlined in the "Guide for the Care and Use of Laboratory Animals" prepared by the National Academy of Sciences and published by the National Institutes of Health (NIH publication 86-23 revised 1985).