GPC1 and schizophrenia: PI-PLC-sensitivity of GPI-APs between schizophrenia and comparison subjects was also determined, with GPC1 [t (14) = 2.19, p = 0.046] and NCAM [t (14) = 2.57, p = 0.022] having decreased sensitivity to PI-PLC treatment in schizophrenia (Fig. 2a, b, Table 3).