TET2 and parathyroid gland carcinoma: At a functional level, the restoration of TET2 activity in the LN229 glioblastoma cell line reduced cell proliferation in vitro, and tumor growth in vivo, which is in agreement with previous work suggesting that TET2 has antitumor activity in leukemias [21, 54] and in other types of tumors including parathyroid carcinoma [55], colorectal cancer [20] and glioma [53].