Although the proband’s clonal lymphoproliferative disorder was immunophenotypically classified as T-cell lymphoma, the lack of molecular classification of her affected sister’s lymphoma in the 1980s prevents us from definitively associating CHST11/MIR3922 deletion specifically with abnormalities of the T-cell lineage. The gene discussed is MIR3922; the disease is T-cell non-Hodgkin lymphoma.