C4A and Alzheimer disease: Ten of the 53 proteins showed significance in the study: complement components (C3, C4, C5), two complement regulators (FH, FI), a soluble form of a complement receptor (sCR1), a classical marker of inflammation (CRP), and three chemokines (eotaxin-1, MCP-1, and MIP-1b), demonstrating high predictability in models comparing AD to CTL