The univariate regression analysis showed that age, sex, interval from initial diagnosis to this treatment, myelofibrosis, splenomegaly, history of HU treatment, thrombus history, and CHR did not affect the decrease in JAK2 mutation burden, while diagnosis and risk stratification did (P = 0.043 and P = 0.032, respectively). This evidence concerns the gene JAK2 and Splenomegaly.