CD34 and acute promyelocytic leukemia: Our results, derived from a well-established and characterized human leukemia cell line (HL-60), widely used as a cell culture model for neutrophil differentiation and as a cell model to set up the basis of the differentiation therapy in acute promyelocytic leukemia [70, 71], together with additional results from primary human CD34+-HPCs and the additional acute promyelocytic cell line NB4, show compelling evidence for the identification of specific miRNA signatures involved in neutrophil maturation, and their dysregulation could lead to pathological conditions, such as cancer.