ZIC1 and schizophrenia: Within the MGE, enrichment of schizophrenia common variant associations was observed in genes with high expression specificity for somatostatin (SST)-positive GABAergic interneuron population (MGE-N-3, markers: SST, MAF; Supplementary figure S6B) and a population predicted to develop into cholinergic neurons (MGE-N-2, markers: LHX8, ZIC1, CNTNAP2; Supplementary figure S6B).