ADORA2A and neoplasm: Because many of the primary tumors in our sample were not well histologically differentiated (48/60 tumors) and were locally invasive (54/60 tumors), future studies should study the expression of PD-L1, CD39, CD73, and A2AR in primary tumors with well-differentiated, non-invasive, and non-metastatic profiles and in distant metastatic lesions to understand the differences in tumor microenvironments between primary tumors and their metastatic lesions.