However, considering the limited in vivo evidence concerning the proteins phosphorylation levels which related to the functional status of PI3K-Akt pathway and the understanding that PI3K-Akt pathway is activated by several different regulatory mechanisms to exert its biological effects [63], the alterations in the DRD2-PI3K-Akt pathway have not been fully elucidated as biological markers of schizophrenia. The gene discussed is DRD2; the disease is schizophrenia.