LEP and acute myeloid leukemia: In clinics, although no significant difference of serum leptin concentrations were found between de novo AML patients and controls in two previous reports [32, 33], two independent investigations by Aref et al. and Bruserud et al. showed that serum leptin levels in AML patients were significantly lower than controls and had negative correlation with percentage of BM blasts and white blood cells [34, 35].