Human embryonic stem cell (hESC) research occupies an exceptional place in science because governments and funding organizations have adopted unique polices to influence research conduct. These policies often extend to the research tools themselves, hESC lines. For example, the U.S. NIH maintains a registry of hESC lines approved for use in research it funds. The U.K. Stem Cell Bank employs a vetting procedure to ensure deposited lines conform to specific requirements.
As a consequence the use of specific hESC lines is a topic of ongoing international interest because utilization patterns serve as a research and evaluation tool. For example, previous studies have examined utilization patterns to evaluate the impact of state-based research programs. McCormic et. al. examined distribution rates and patterns of hESC line utilization as an indicator of state research capacity. Karmali et al. examined the use of hESC lines not eligible for NIH funding as an indicator of the efficacy of state-funded stem cell research programs. These studies quantified transfers of selected hESC lines or reported surveys of hESC line requests as indicators or proxies to support their analysis.