CCND1 and B-cell non-Hodgkin lymphoma: 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.