Map of putative chromosome 8p21-22 schizophrenia susceptibility loci on 8p and diagram of the genomic structure of PCM1 showing the relative positions of exons, introns, and genetic markers. Distances are shown in megabases of DNA. PCM1 indicates pericentriolar material 1; PPP3CC, calcineurin; DRP2, dihydropyrimidinase-related protein 2; FZD3, frizzled; and NRG1 , neuregulin.