Using a CD200 ELISA to detect biologically active sCD200 in culture supernatant, we determined that primary human BCC exhibited significantly higher levels of sCD200 (291.9 ± 21.10 pg/106 cells [n = 6]) than primary human normal skin (213.50 ± 22.31 pg/106 cells [n = 4]; P < 0.05; Figure 5A). The gene discussed is CD200; the disease is skin basal cell carcinoma.