Hayashi et al favored 5% as the cutoff value for indolent PTCL,[2] while Perry et al used 10% as the cutoff for indolent T-cell lymphoproliferative disease of GIT.[7] Therefore, establishing the entity of indolent T-cell lymphoma as well as the criteria for Ki-67 LI, are required. The gene discussed is MKI67; the disease is mature T-cell and NK-cell non-Hodgkin lymphoma.