1. Patients with naïve or sensitive rituximab indolent non-follicular and mantle cell non-Hodgkin's Lymphoma disease that had failed to respond or relapsed after primary therapy. There is a demonstrated progressive disease requiring further treatment. Histological subtype included into the study are are as follows Small lymphocytic/lymphoplasmocytic lymphoma; Nodal marginal zone Lymphoma (MALT lymphoma are excluded) Splenic marginal zone lymphoma Mantle cell lymphoma A lymphnode biopsy is advisable if it is not harmful for the patients, before enrollment of the patient into the study in order to confirm diagnosis and to rule out histologic transformation. Lymphnode biopsy should be performed within 6 months before study entry.