Ethics Review A study conducted in 2016 by Freund J, May RM, Yang E, Li H, McCullen M, Zhang B, et al. was designed to analyze the development of natural killer (NK) cells in mice. The study, lead by the principle investigator Taku Kambayashi, used selectively bred mice between the ages of 10 and 12 weeks that carried specific receptors (Ly49A, Ly49G, Ly49C, and Ly49I). These receptors generically code for the NK cells to either expand, respond or differentiate into memory-like cells. I believe the study conducted complied with the ethical standard. The study used carbon dioxide to euthanize mice under the University of Minnesota IACUC protocol (#804ff03, 804245). The mice themselves were housed in pathogen-free conditions and treated in strict compliance with the Institutional Animal Care and Use Committee regulations at the University of Pennsylvania. Most of the mice were bread on campus but some had to be purchased from The Jackson Laboratory and Charles River Laboratories. This project was funded in part with federal funds from the National Cancer Institute, National Institutes of Health and the Centre for Cancer Research. The funders are very highly regarded nationally and world wide and I believe this restricts the possible of false results and furthermore the funders had no role in study design, data collection, and analysis, decision to publish, or preparation of the manuscript. The size of the mice euthanized might be considered unethical however the study used the minimum amount of mice to produce and appropriate sample size to cancel out any anomalous data. As the study by, Freund J, May RM, Yang E, Li H, McCullen M, Zhang B, et al., worked with mice and used chemistry to make conclusions about the mice gene (DNA) content, it most certainly had the ability to be conducted
unethically. Although, I believe than this study was ethically sound and complies with all ethical standards applicable to the study. 2