Given the various roles of TETs in biological processes, it comes as no surprise that it has been proposed as an important therapeutic target for diseases such as cancer.113,114,252,255,256 For example, vitamin C, by improving TETs activity, allows leukemia cells to be more sensitive to PARP inhibitors.246 Interestingly, cells with TET2 mutations, possibly heavily relying on compensatory roles of TET1/3, showed more vulnerable to TETs inhibitors compared with normal ones. The gene discussed is TET2; the disease is cancer.