Primers for real-time PCR (the location of the numbered primers was shown in Figure 3A ) Endogenous human full-length CD200 (1) sense (exon 2) 5 0 -CAGCCTGGTTTGGGTCATG-3 0 (2) antisense (exon 3) 5 0 -GCAGAGAGCATTTTAAGGAAGCA-3 0 Endogenous human truncated CD200 