PDCD1LG2 and cancer: We next examined PD-L2 expression using immunohistochemistry (IHC) in ccRCC tissue array, and found that PD-L2 expression pattern was unexpectedly changed with the higher extracellular expression in cancer tissues, in contrast to the higher cellular localization of PD-L2 in the adjacent tissues (Fig. 1A), indicating extracellular PD-L2 may regulates progression of ccRCC.