The results of Liu, Weng & Weng (2009), showed that patients with SLE had significantly increased percentages of PD-1-expressing CD3+T cells and CD19+B cells, PD-L1-expressing CD19+ B cells, and PD-L2-expressing CD14+ monocytes. The gene discussed is PDCD1LG2; the disease is systemic lupus erythematosus.