BD-associated loci showed no significant difference from propensity of a random locus to fall in a genomic regulatory block, however, there was a marked increase in ASD-GWAS and SCZ-GWAS detected loci overlapping a genomic regulatory block, indicating a role of genes involved in developmental transcription factors and/or cell adhesion, cell-cell signalling, axon guidance genes (all are enriched among GRB target genes) in molecular mechanisms leading to autism and schizophrenia. The gene discussed is GZMB; the disease is schizophrenia.