ABSTRACT
The history of embryonic stem (ES) cells is intimately linked with the history and study of embryonal carcinoma (EC) cells derived from teratocarcinomas. Whether ES cells would have been discovered and studied in the same way without the previous studies of EC cells is a moot point, but it is clear that the earlier study of mouse EC cells (1,2) did provide many of the tools and concepts used in the derivation and study of ES cells, as well as the original rationale for their isolation (3,4).
