APOE and early-onset autosomal dominant Alzheimer disease: Our previous observation of C1q-ApoE complexes in atherosclerosis and Alzheimer’s Disease and the characterization of ApoE as a potent checkpoint inhibitor of the CCC (1, 2) raised an important question: does the C1q-ApoE complex represent a common universal pathology of all diseases in which the CCC is active (3, 4)?