HTR1A and schizophrenia: The CHRNA7 gene is involved in the sensory processing endophenotype seen that is seen in patients with schizophrenic patients [153].However, hypermethylation of genes that regulates serotonin signaling (5-hydroxytryptamine receptor 1A (5HTR1A) and serotonin type 2A receptor (HTR2A) receptors and serotonin transporter (5-HTT) were found to be associated with schizophrenia [154,155,156].