BST2 and thyroid cancer: For example, BST2 levels are significantly downregulated in lung squamous cell carcinoma, kidney papillary cell and chromophobe carcinoma, liver cancer, prostate cancer and B-cell acute lymphoblastic leukemia, and BST2 levels are unchanged in lung adenocarcinoma and thyroid cancer.15, 19 Thus, the role of BST2 in NPC remains unclear.