Alike the all positive haplotype; KIR haplotype No. 5, the inhibitory haplotype No. 1—positive for all 8 inhibitory KIR genes—confers a weak protection (P = 0.006, OR (95%CI) = 0.67(0.50–0.89)) against RA. The gene discussed is KIR3DL1; the disease is rheumatoid arthritis.