The tumor-suppressive role of TET1 in hematopoietic malignancies was highlighted by Cimmino et al,42 who demonstrated that TET1 deletion in mice induced B-cell lymphoma with mutations resembling those found in non-Hodgkin B-cell lymphoma, accompanied by hypermethylation and silencing of TET1. Here, TET1 is linked to B-cell non-Hodgkin lymphoma.