MDGA2 and schizophrenia: To test whether there are abnormalities in GPI-dependent membrane association, we identified several brain-expressed GPI-APs previously associated with schizophrenia, glypican 1 (GPC1)28,29, neural cell adhesion molecule 1 (NCAM)30,31, MAM domain-containing GPI protein 2 (MDGA2)32, and ephrin type A receptor (EPHA1)33.