GSTM1 and acquired polycythemia vera: Multivariate analysis incorporating variables including gender, age, diagnosis (PV+ET), coronary heart disease, thrombotic events before diagnosis, smoking history, Hb ≥ 136 g/L, HCT ≥ 0.42, D-dimer ≥ 1 mg/L, DFR ≥ 0.243, and JAK2V617F mutation, revealed that PV/ET diagnosis (OR = 3.311, P = 0.004), thrombotic events before diagnosis (OR = 5.161, P < 0.001), and D-dimer ≥ 1 mg/L (OR = 3.360, P = 0.002) were independent risk factors for thrombotic events at initial diagnosis in MPN patients (Table 3).