I will make some comments but, since I am not clinically trained, I am hoping that @Christian_Reich and @hergchan will also chime in. In working with other clinical scientists, I have often heard that there a number of potential issues with animal data that make pharmacologic observations in such systems less trustworthy for supporting claims about what can occur in humans. These include differences in biochemical pathways, gene and protein function and structure, and the difficulty in identifying phenotypes that map to human conditions (e.g., depression). For this reason, it makes sense to me to provide some tag that will help client systems show those users who care when an evidence item is based on animal research. This costs almost nothing to do and the potential benefit for certain investigations would be large. I think of Laertes as being oriented toward helping research drug-HOI associations that occur in humans. I think @Christian_Reich’s question about bringing in all products approved only for animals might make sense if someone wanted to work deeply with animal data. Right now, my proposal is to address the fact that more than a quarter and maybe even more than half of the evidence from certain literature sources (SemMed and now CTD) will be probably be from animal studies.