All research involving human participants, human remains, cadavers, tissues, biological fluids, embryos or fetuses, must have been approved by the authors' institutional review board or equivalent committee(s). This committee must be independent of the researcher, the sponsor and any other undue influence, must have the right to monitor ongoing studies and, also, must be named in the manuscript. For research involving human participants, informed consent must have been obtained and all clinical investigation must have been conducted according to the principles expressed in the Declaration of Helsinki (1964) last updated in 2008. This declaration was developed by World Medical Association (WMA), and is a statement of ethical principles for medical research involving human subjects, including research on identifiable human material and data. According to these guidelines, all research involving human subjects should be carried out in accordance with the fundamental ethical principles of respect for human dignity, respect for free and informed consent, respect for vulnerable persons, respect for privacy and confidentiality, respect for justice and inclusiveness, beneficence. The design and performance of each research study involving human subjects must be clearly described in a research protocol that describe the scientific background, objectives, design, methods of data collection and analysis, risks and benefits of the proposed research and qualifications of the investigators. The research protocol, also, should include information regarding funding, sponsors and institutional affiliations. No change to the protocol may be made without consideration and approval by the committee. For medical research using identifiable human material or data, physicians must normally seek consent for its collection, analysis, storage and/or reuse. In cases where consent would be impossible or impractical to obtain the research must be done only after consideration and approval by a research ethics committee. For studies involving humans categorized by race/ethnicity, age, disease/disabilities, religion, sex/gender, sexual orientation, or other socially constructed groupings, authors should make explicit their methods of categorizing human populations. Also at every stage of research must always be used a correct, acceptable and appropriate terminology.