The iNSCs were established from human NPC patient-derived skin fibroblasts (GM03123, GM18453; Coriell Institute for Medical Research, USA) and were characterized in a previous study [18 (link)]. The pMX-SOX2 and pMX-HMGA2 retroviral constructs were transfected into 293 FT cells (Invitrogen, USA) to produce high viral titers using FuGENE 6 Transfection Reagents (Roche Diagnostics, USA) and the viral supernatants were collected and used to infect NPC patient-derived fibroblasts. The transduced fibroblasts were cultured in NSC maintenance medium (ReNcell NSC Maintenance Media; Millipore, USA) with basic fibroblast growth factor (bFGF; Sigma, USA) and epidermal growth factor (EGF; Sigma) added to induce neural stem cells. NSC-like colonies were picked and cultured under neurosphere conditions as attached cells on poly-L-ornithine- and fibronectin-coated dishes repeatedly to generate homogenous iNSCs. As reported previously, the iNSCs showed an NSC-like morphology and expressed NSC-specific markers such as PAX6 and NESTIN. Furthermore, the iNSCs demonstrated differentiation into neurons, astrocytes, and oligodendrocytes, indicating that the generated iNSCs could function as NSCs.