Both human ESCs and iPSCs have been used for modeling human genetic diseases. The earlier models were developed using ESCs9, but following the advent of human iPSC technology, human iPSCs have become the preferred option because of their availability and lack of potential ethical concerns associated with human ESCs. Human iPSCs are very similar to human ESCs. Both types of cells express human pluripotent factors and ESC surface markers, and exhibit developmental potential to differentiate into three germ layers2,3. Residual epigenetic memory of somatic cells could occur in iPSCs10–12, which may affect the differentiation potential of these cells13. Although the persistence of epigenetic memory of parental cells has been reported in iPSCs10–12, similar phenotypes have been reported in disease modeling using human ESCs and iPSCs in most cases13, validating the effectiveness of disease modeling using patient-derived iPSCs.
