Previous studies in leukemia suggested that an independent active process may naturally exist in HL-60 cells to eliminate the extrachromosomal amplification of MYC and that this process can be enhanced by drugs including a low dose of HU or dimethyl sulfoxide.252 A low dose of HU increases the percentage of spontaneously differentiated cells where the amplification of MYC is decreased by entrapment within micronuclei.147,249 Understanding the molecular mechanisms of the natural elimination process has important implications for drug intervention in leukemia. Here, MYC is linked to leukemia.