PDCD1LG2 and cancer: Both the resected tumor and tumor-adjacent normal tissues were used for two purposes: (1) to evaluate the expression of PD-L1, PD-L2, and PD-1 in tumor cells, in cells of the tumor microenvironment (TME), in epithelial cells, and in cells of the stromal microenvironment (SME); and (2) to derive ex vivo primary culture of cancer-associated fibroblasts, TCAFs (CAFs derived from tumor tissues), and NCAFs (CAFs derived from tumor-adjacent normal tissues) from the tumor tissue and tumor-adjacent normal tissues, respectively.