In the NAc, the expression levels of DARPP-32 and CaN showed no significant differences in schizophrenia patients relative to controls (t [23.14] = 1.54, p = 0.138; and t [34.16] = 1.56, p = 0.127; respectively; Figs 1b and 2b); by contrast, each mean of two protein expressions in bipolar patients were higher than that of controls respectively (Figs 1b and 2b). Here, PPP1R1B is linked to schizophrenia.