LCN2 and acquired polycythemia vera: Neutrophil gelatinase‐associated lipocalin (NGAL) is known as a biomarker related to acute renal injury, but was also referred to as an adipokine due to its association with inflammation.4, 5 The association of NGAL with inflammation has been demonstrated in several studies.5 In addition, the NGAL level has been reported to increase in individuals with hematological malignancies such as chronic myeloid leukemia (CML), polycythemia vera (PV), and essential thrombocythemia (ET).5, 6, 7, 8