RPTOR and Alzheimer disease: However, it is possible that the reduced Raptor (but not Rictor) association with mTOR in healthy control versus AD lymphocytes might indicate that different downstream signaling pathways for mTORC1 are prominent in the diseased versus normal lymphocytes, because differential binding of Raptor/Rictor to mTORC1/2 can affect substrate specificity for mTOR (Hay and Sonenberg, 2004; Su and Jacinto, 2011).