In addition to changes in 5‐HT activity, postmortem and in vivo studies of patients with schizophrenia have revealed changes in the expression of 5‐HTR and SERT, with most studies focused on the roles of 5‐HT1AR and 5‐HT2AR. However, findings about the role of 5‐HT1AR in schizophrenia remain inconsistent. The gene discussed is SLC6A4; the disease is schizophrenia.