Moreover, our results show that CALR-mutated CD34+ cells, which exhibit greater increase of intracellular ROS, have a higher apoptosis level compared to JAK2-mutated ones, suggesting that mutated-CALR patients could activate protective mechanisms promoting cell death, while a moderate increase of ROS induces a lower level of cell death and could permit the survival of cancer cells allowing disease progression. Here, CALR is linked to cancer.