In the PFC, we found that the expression levels of DARPP-32 evinced a significant decrease in patients with schizophrenia relative to controls (t (40.14) = 2.12, p = 0.040) (Fig. 1a) and that the expression of CaN tended to increase in patients with schizophrenia (t (40.72) = 1.97, p = 0.056) as compared with controls; the mean of CaN expression in 6 patients with bipolar disorder was higher than that of controls (Fig. 2a). This evidence concerns the gene PPP1R1B and bipolar disorder.