RGS2 and Alzheimer disease: Melatonin treatment has been suggested to ameliorate AD pathology and cognitive decline in animal models.68, 69, 70 Notably, melatonin production in the rat pineal gland was reduced following Rgs2 transfection.71 Lower RGS2 expression in AD LCLs, blood and brain (Figure 3a, Figures 4c–f) may indicate enhanced melatonin production.