PRIMA study: PFS according to CLC and maintenance group. (A) Patients with follicular lymphoma and leukemic cells (CLC) treated without rituximab maintenance after induction regimen presented a worse PFS than patients with follicular lymphoma without CLC who were treated without rituximab maintenance. LC^+/−, presence/absence of circulating lymphoma cells. (B) With rituximab maintenance therapy, patients with and without CLC presented similar PFS.