MAPK8 and schizophrenia: However, at the single time point studied here, there was no change in hippocampal expression or phosphorylation of JNK or p38 themselves, nor of proteins such as 14-3-3ε, c-Jun, GSK-3β, β-Catenin and HSP90 which have been associated with schizophrenia and may represent additional treatment targets [92, 108–111].