While the clinical significance of PD-L1, the main ligand for PCD-1, has been widely investigated in cancer, the role of PD-L2 expressed by the immune, stromal, and tumor cells has received less attention and has been considered less relevant in predicting responses to immune checkpoint blockade with anti–PD-1/PD-L1 agents.15 Here, PDCD1LG2 is linked to neoplasm.