This letter should be uploaded through online system as a word file. By an official letter corresponding author should introduce the manuscript briefly and state that:

1. The manuscript is original work of author. All data, tables, figures, etc. used in the manuscript are prepared originaly by authors, otherwise the sources are cited and a 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 The manuscript has not been and will not be published elsewhere or submitted elsewhere for publication.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: (1) informed consent was obtained from each patient included in the study and (2) the study protocol conforms to the ethical guidelines of the 1975 Declaration of Helsinki as reflected in a priori approval by the institution\'s human research committee. 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).
5. Informed Consent: to see templates click here.
6. Getting access to the template of cover letter, kindly click HERE.