ENTPD1 and sarcoma: Increased expression of CD39 has been widely reported in several tumors, such as medulloblastoma (214), sarcoma (215), HCC (216), pancreatic cancer (217), colorectal cancer (218, 219), gastric cancer (216), and endometrial cancer (220); as well as in infiltrating immune cells (216, 221–224) and tumor endothelial cells (216, 225), influencing tumor growth, metastasis and angiogenesis.