Gene mutations are the most common cause of cancer. Some genes are called tumor suppressors because loss of these genes will have a high tendency in inducing cancer. CHC1-L is proposed to be such a tumor suppressor for myeloma. To confirm this hypothesis, we are creating a mouse mutation with a defect in CHC1-L gene function. This study will define a molecular mechanism for myeloma genesis and the mutated mice could be served as a disease model.