The results of the rituximab maintenance phase III trial demonstrated that patients with FL who continued to take rituximab monotherapy as a maintenance therapy after responding to an initial course of chemotherapy combined with or without rituximab experienced longer progression-free survival durations than did those who received no rituximab maintenance therapy. The efficacy of maintenance treatment after first-line induction treatment with R-chemotherapy was addressed in the international PRIMA (Primary Rituximab and Maintenance) study, which has enrolled 1,217 patients. The first results are eagerly awaited. Although MZL has better prognosis in TTP and OS than FL, both of them are classified as the same category of indolent lymphoma -characterized by frequent relapse and prolonged survival.