Research in human induced pluripotent stem cells (hiPSCs) is rapidly developing and there are expectations that this research may obviate the need to use human embryonic stem cells (hESCs), the ethics of which has been a subject of controversy for more than 15 years. In this study, we investigated approximately 3,400 original research papers that reported an experimental use of these types of human pluripotent stem cells (hPSCs) and were published from 2008 to 2013. We found that research into both cell types was conducted independently and further expanded, accompanied by a growing intersection of both research fields. Moreover, an in-depth analysis of papers that reported the use of both cell types indicates that hESCs are still being used as a “gold standard,” but in a declining proportion of publications. Instead, the expanding research field is diversifying and hESC and hiPSC lines are increasingly being used in more independent research and application areas.
In this article, Löser, Kobold, and colleagues investigate recent trends in research involving human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs). They show that research has expanded during the past 6 years, and that research in hESCs and hiPSCs partially overlaps. However, they show that the two cell types dominate different fields of research, and a predominant use of hESCs as a “gold standard” in hiPSC research was not observed.