In the ET group (n = 23), the JAK2 V617F heterozygote mutant cases (n = 13) were similar in terms of sex, WBC, Hb, and MPV, to non mutated cases (n = 10) while the average age of the mutated group, was found to be significantly lower (Table 4). This evidence concerns the gene GSTM1 and essential thrombocythemia.