GRIK2 and schizophrenia: Fine-mapping/exome sequencing also identified coding variants associated with substantial risks for schizophrenia in the NMDAR (GluN2A), the AMPAR (GluA3), the KAR (GluK2 and GluK4), and PSD-95-associated genes (SHANK, NLGN, and DLGAP) and serine racemase (SR) [90,91].