 Since immunoglobulins are essential to a lymphocyte and highly expressed to increase detection of antigens, c-myc is then also highly expressed, leading to transcription of its targets, which are involved in cell proliferation.Mantle cell lymphoma is characterized by fusion of cyclin D1 to the immunoglobulin locus.Cyclin D1 inhibits Rb, a tumor suppressor, leading to tumorigenesis.