Moreover, melatonin treatment of multiple sclerosis patients upregulated SIRT1 expression in their blood cells72 and reduced sepsis-induced brain injury through upregulation of Sirt1 and Bcl-2 in mice.73 Thus, lower RGS2 expression in AD may allow higher pineal melatonin production and in turn improve neuroprotection. Here, BCL2 is linked to Alzheimer disease.