Disease modeling using primary patient-derived cells is helpful for studying the etiology of human diseases and developing therapeutic strategies for these diseases. However, the unavailability of expandable sources of primary cells from patients, especially hard-to-access cells such as brain cells and heart cells, is a critical limitation. Human iPSCs are therefore an attractive alternative because of the ease with which human diseases (particularly those with defined genetic causes) could in principle be modeled using iPSCs derived from easily accessible cell types, such as skin fibroblasts and blood cells from diverse patients. Because of their intrinsic properties of self-renewal and potential to differentiate into nearly any cell types in the body, patient-specific iPSCs could provide large quantities of disease-relevant cells and a variety of different cell types that were previously inaccessible, such as neurons and cardiomyocytes. Furthermore, because iPSCs can be derived from the relevant patients themselves, they could enable personalized disease modeling that would be a central part of precision medicine.
