Accumulating information from disease iPSC research, in combination with patients’ personalized clinical experience, will aid “disease repositioning”, in which diseases are defined not by clinical but by cellular phenotypes. If analysis of the cellular phenotypes of in vitro iPSC models of clinically different diseases indicates that the phenotype is the same or similar, then a treatment that is effective in one condition may be effective in the others. For example, an iPSC model of bipolar disorder identified hyperexcitable neuronal cells201. Similar hyperexcitability was found in iPSC-derived motor neurons from a patient with amyotrophic lateral sclerosis203. Therefore, the same therapeutic agent may be effective for these clinically disparate but cellularly similar diseases. Accumulating data of cellular phenotypes of iPSC models from a cross-sectional variety of diseases may contribute to new stratifications and understanding of different diseases, which could also lead to new cross-sectional treatment approaches.
