Additionally, B12 increased MHC class II expression in Tet2-deficient monocytes, a marker of poor prognosis in AML (37), and enhanced LPS-induced cytokine responses of myeloid cells in vitro, the latter implying a cell-intrinsic synergy between B12 and Tet2-deficiency. This evidence concerns the gene TET2 and acute myeloid leukemia.