Combined with our findings of unchanged Hexb, CD68, and IBA1 mRNAs in high inflammation schizophrenia, as well as previous studies reporting no change in microglial cell number or density in cortical gray matter in schizophrenia (Arnold et al., 1998; Steiner et al., 2006, 2008), it seems likely that patients may not have a deficit in microglia numbers but a deficit in microglial responsiveness. This evidence concerns the gene HEXB and schizophrenia.