MCL1 and plasma cell myeloma: Such observations gain added significance in light of the observation that MCL1 maps to a region of gene amplification in aggressive human MM primary tumors and prompt speculation that MCL1 and BCL2 play critical roles in the progression of human myeloma (Carrasco et al., 2006; Le Gouill et al., 2004; Mitsiades et al., 2004)—a theory that can now be tested in this genetic model system.