By separating paranoid schizophrenia from residual schizophrenia, differences in S100b-positive cells were observed.79 Microglia are also elevated in paranoid schizophrenia, where HLA-DR-positive cell density is higher in paranoid schizophrenia compared with residual schizophrenia.88 Moreover, differences in gliosis score are seen between early onset and late onset schizophrenia.135 Similarly, the three patients with microgliosis in the study by Bayer et al.85 were all defined to have late onset schizophrenia. This evidence concerns the gene S100B and schizophrenia.