C-reactive protein (CRP) is an evolutionarily conserved acute-phase plasma protein composed of five identical pentameric subunits 1. CRP functions as a pattern recognition receptor mediating innate immunity through calcium-dependent binding to phosphocholine and other ligands 2. Its primary mechanism involves complement activation, opsonization, and phagocytosis enhancement through interactions with leukocyte CRP-receptors via a conserved cell-binding peptide (residues 31-36: KAFTVC) 3. CRP also binds dead and damaged cells, promoting their clearance 4. In disease pathogenesis, CRP contributes to atherosclerosis through a feedback loop with oxidized LDL and the LOX-1 scavenger receptor on endothelial cells 5. During influenza infection, CRP modulates metabolic reprogramming and immune homeostasis, with both protective and potentially pathogenic roles 6. Clinically, serum CRP levels serve as a faithful biomarker of inflammation severity and treatment response, though its biological effects occur even at baseline levels 7. CRP also exerts pro-inflammatory effects on vascular cells and can exacerbate tissue damage through complement activation 4. Notably, no genetic CRP deficiency has been reported in humans, and therapeutic CRP inhibition is being explored for diseases including atherosclerosis and cancer 7.