In order to target IL-2 to tumor in a way of reducing its potential toxicity, Merck KGaA (Darmstadt, Germany) developed a novel fully humanized IL-2 fusion protein, EMD521873 or NHS-IL2LT (Selectikine), for the treatment of solid tumors and B-cell non-Hodgkin lymphoma [17]. The gene discussed is IL2; the disease is B-cell non-Hodgkin lymphoma.