PDCD1LG2 and neoplasm: With χ2-test analysis, we found that high stromal expression of PD-L2 was negatively correlated with age (Pearson's R=-0.108, P=0.011), tumor T classification (Pearson's R=-0.123, P=0.004), recurrence and metastasis (Pearson's R=-0.127 P=0.003) and clinical stage (Pearson's R=-0.111 P=0.009), respectively (Table 2), while there was no significant association with other clinicopathologic features, such as patient sex, N classification and histological type (P>0.05, Table 2).