LCN2 and acquired polycythemia vera: However, in previous studies, the CML and PV groups showed statistically higher NGAL levels than the control group.6, 7 The MPN group having higher NGAL levels than the control group (normal BM) may be attributable to the increase in the levels of neutrophilic precursors and mature neutrophils in BM, which leads to an increase in the synthesis and secretion of NGAL.