Secondly, from the molecular perspective, research respectively confirmed that cysteine–cysteine chemokine receptor type 5 (CCR5) delta 32 polymorphism conferred susceptibility to both RA in Europe with a significant negative association and pre-eclampsia in the population consisting of Caucasians with the same allele (28, 29). The gene discussed is CCR5; the disease is rheumatoid arthritis.