CD70, a type 2 transmembrane glycoprotein belonging to the tumor necrosis factor (TNF) ligand family, was found to be highly expressed in malignant hematopoietic stem cells and solid tumors and constitutively expressed in activated T-cell leukemias and lymphomas in previous studies, indicating its potential as an immunotherapeutic target [72]. The gene discussed is TNF; the disease is T-cell leukemia.