In atherosclerosis, complement receptors (CR1, CR2, CR3, gC1q‐R as well as C3aR and C5aR) were identified to be expressed in plaques, and the mRNA levels of C1r, C1s, C4, C7 or C8 were found to be upregulated, whereas local productions of regulators including CD46, C1–INH, C4BP, DAF and CD59 were also detected. The gene discussed is CR1; the disease is atherosclerosis.