Follicular Lymphoma (FL) is a cancer of a B lymphocyte, a type of white blood cell. FL is typically a slowly progressing but incurable disease. Follicular lymphoma cells produce a specific defect in the patient's immune system impairing their ability to control their cancer. Lenalidomide has been shown to reverse the specific immune defect caused by FL in the patient. By including lenalidomide, the RELEVANCE study aims to eliminate the cancer while restoring the patient's immune competence.