Mantle cell lymphoma (MCL) is an incurable B cell non-Hodgkin's lymphoma, characterized by the t(11; 14)(q13; q32) translocation that juxtaposes the proto-oncogene CCND1, which encodes cyclin D1 (cycD1), downstream of the immunoglobulin heavy chain gene promoter. Here, CCND1 is linked to mantle cell lymphoma.