Generation and Maintenance of hiPSCs

WT- and NS-iPSCs were previously generated from their respective dermal fibroblasts [24 (link)]. hiPSCs were maintained in hiPSC medium on mitomycin C (AG Scientific, San Diego, CA, USA)-treated mouse embryonic fibroblasts (feeder). The hiPSC medium consisted of DMEM/F-12 (Gibco, Thermo Fisher, Waltham, MA, USA) supplemented with 20% KnockOut™ serum replacement (Gibco), 1% penicillin-streptomycin (Gibco), 1% MEM non-essential amino acids solution, 0.1 mM β-mercaptoethanol (Sigma-Aldrich, Merck, Darmstadt, Germany), 1.2 mg/mL sodium carbohydrate (Sigma-Aldrich, St. Louis, MO, USA), and 10 ng/mL recombinant human bFGF (R&D Systems, Minneapolis, MN, USA). The hiPSCs were incubated at 37 °C in an atmosphere containing 5% CO₂ with a daily medium change, and passaged every 6 days.