Inclusion Criteria:  Age 18 and above. FL grade I-IIIa, according to world health organization (WHO) classification, in patients who were not previously treated with chemotherapy, have a high tumor bulk & an indication for treatment, as defined by the Groupe d'Etude des Lymphomes Folliculaires (GELF) criteria. Eastern Cooperative Oncology Group (ECOG) performance status grade 0-2. The presence of a molecular marker in bone marrow or peripheral blood for MRD assessment.  Exclusion Criteria:  FL grade IIIb. HIV infection. HBsAg positivity. Active malignancy other than FL Pregnancy or lactation.