Given that reduced 5-hmC is a hallmark of several myeloid malignancies that often exhibit reduced levels of TET2, including in AML, MPN, and CMML (50, 51), and given the link between intracellular metabolism, epigenetic modifications, and increased Ca2+ influx in cells, we speculated that a reduction in 5-hmC in Tet2–/– Ob/Ob HSC/Ps is at least associated with increased levels of Ca2+ in HSC/Ps in these mice. The gene discussed is TET2; the disease is chronic myelomonocytic leukemia.