Interactions of PD-1 with PD-L1/PD-L2 have been reported in a wide variety of solid tumors and hematologic malignancies, with patients having tumors positive for PD-L1 or PD-L2 showing dramatically lower survival rates than those having tumors negative for both of these ligands (46% vs. 83% for 5-year survival) 46. This evidence concerns the gene PDCD1LG2 and hematologic disorder.