CREG1 and systemic lupus erythematosus: In conclusion, it was evident that there are differences in the patterns of expression of Creg proteins on the peripheral blood cells from SLE patients, since the diminished MFI expressions of all Cregs proteins were found on neutrophils cells; CD55, CD59, and CD46 on lymphocytes; CD55 on monocytes; CD59 and CD35 on RBC.