With the advent of human induced pluripotent stem cell (hiPSC) technology, it is now possible to derive patient-specific cell lines that are of great potential in both basic research and the development of new therapeutics for human diseases. Not only do hiPSCs offer unprecedented opportunities to study cellular differentiation and model human diseases, but the differentiated cell types obtained from iPSCs may become therapeutics themselves. These cells can also be used in the screening of therapeutics and in toxicology assays for potential liabilities of therapeutic agents. The remarkable achievement of transcription factor reprogramming to generate iPSCs was recognized by the award of the Nobel Prize in Medicine to Shinya Yamanaka in 2012, just 6 years after the first publication of reprogramming methods to generate hiPSCs (Takahashi, K., Tanabe, K., Ohnuki, M., Narita, M., Ichisaka, T., Tomoda, K., and Yamanaka, S. (2007) Cell 131, 861-872). This minireview series highlights both the promises and challenges of using iPSC technology for disease modeling, drug screening, and the development of stem cell therapeutics.The minireviews in the series cover topics including the use of differentiated cells derived from induced pluripotent stem cells (iPSCs), 2 such as heart cells (cardiomyocytes), in toxicity assays with new or existing therapeutics and the use of iPSCderived cells for drug screening both for new drug candidates and repurposing of existing drugs. Three minireviews focus on the problems of using iPSC-derived cells in regenerative medicine: immune issues for autologous therapy will be considered in one minireview; the issue of genetic instability in iPSCs and iPSC-derived cells will be considered in the second; and preclinical studies with iPSCs and iPSC-derived cells will be discussed. Finally, molecular techniques for correction of gene mutations in iPSCs will be covered.In the first minireview of the series, Kyle Kolaja discusses "stem cells and stem cell-derived tissues and their use in safety assessment" (1). Toxicology research has traditionally relied on animal studies to provide preclinical safety assessment of various therapeutic agents under development. With the advent of stem cell and iPSC technology, these cells and their differentiated counterparts provide an attractive alternative to animal testing. In this article, Kolaja discusses the state of the art for a number of stem cell-derived tissues and their application in toxicology research. Kolaja proposes that future toxicology studies will integrate genetic diversity in screening as well as complex in vitro derived organoids, three-dimensional models of human organs.In the second minireview, Sandra J. Engle and Fabien Vincent discuss "small molecule screening in human induced pluripotent stem cell-derived terminal cell types" (2). Because hiPSCs offer a means to generate genetically defined cellular disease models, there is tremendous potential in using hiPSC-derived cell types for drug screening. Engle and Vincent discuss small molecule...