TET1 and Lymphadenopathy: All TET enzymes are upregulated at the mRNA level in TCRαβ thymocytes during selection (ImmGen RNAseq database), but we examined mutants for TET1 and TET3 because TET2/3 DKOs have a severe defect in T cell differentiation in the thymus and mice develop severe lymphadenopathy and weight loss at 3–5 weeks of age (unpublished observations26).