TET1 and cancer: The TET family is thought to act as tumor suppressors by maintaining other tumor suppressor genes in their unmethylated state.31, 35 Indeed, loss of function mutations in TET2 are frequently found in hematological malignancies and have been implicated in promoting tumor progression.35 Recently, analysis of microRNA-target mRNA expression correlations across 11 human cancer types in TCGA showed that TET1 was significantly inversely correlated with miR-29b across all cancer types.36 We provide mechanistic evidence that miR-29b directly downregulates TET1 expression (Figure 5).