These have included hiPSC-differentiated: astrocytes and OPC with GFAP aggregate and deficient myelination phenotype for studying Alexander disease; types of neurons, NPC, or NPC spheroids with Rett syndrome mutations, major depressive disorders, or potential genetic variants from Dravet syndrome; α1 subunit of L-VOCC Cav1.2 (CACNA1C variant) gain-of-function-related forebrain neurons for modeling Timothy syndrome; hippocampal neurons and NPC as an in vitro model of bipolar disorder; genetic deletions or duplications-caused or idiopathic schizophrenia models in almost all neural cell types. The gene discussed is CACNA1C; the disease is bipolar disorder.