In PTCL one of the candidate oncogenes is STAT1 (Signal transducer and activator of transcription 1), whose inappropriate activation has been observed in a variety of malignant cells from breast cancer, head and neck squamous carcinoma, melanoma, lymphoma and leukemia, suggesting that STAT1 may under specific conditions contribute to malignant transformation23. The gene discussed is STAT1; the disease is leukemia.