Understanding and treating many diseases have been constrained by the absence of in vitro models, especially because culturing primary cells affected by the diseases is very challenging. Limitations primarily lie in the access to patient's tissues as the priority goes for diagnosis, in addition to the complications in obtaining some cell types, such as neural or cardiac tissues, and to maintaining these cells in vitro. However, the development of stem cell studies and the novel discovery of iPSCs provided an important source of cells to conduct in vitro studies (Unternaehrer and Daley, 2011). Such establishment of human iPSCs (hiPSCs) has led to new clinical strategies for using them as universal sources in regeneration therapy of damaged organs and tissues (Pei et al., 2010). Moreover, iPSCs generated from a patient affected by a certain disease possibly reproduces the disease phenotype (Egashira et al., 2011). In view of this, different kinds of patient-specific iPSCs have been generated to model human neurodegenerative diseases, such as Parkinson's disease (PD) (Byers et al., 2012), Huntington's disease (HD) (Nekrasov et al., 2016), Amyotrophic lateral sclerosis (ALS) (Chestkov et al., 2014), and Alzheimer's disease (AD) (Mungenast et al., 2016).
