18, retrospectively, investigated long‐term development of hematologic and non‐hematologic SM in 331 ET patients, analyzing possible association with chemotherapy treatments. The results of the analysis showed that treatment of ET patients with ALK was associated with a significantly increased risk of developing second hematologic malignancy (P = 0.03), while no association with treatment was observed as to the risk of developing non‐hematologic malignancy (P = ns). These results are in agreement with ours, as shown in Table 3. This evidence concerns the gene ALK and essential thrombocythemia.