“…In particular, it may result in the improvement of the delivery of drugs for patients suffering from blood disorders. Not surprisingly, many authors have been interested by the modeling and the analysis of hematopoiesis, including, [19], [5], [4], [1], [2], [20], [3], [8], [13] and [24], to name but a few. In the present contribution, to obtain a coupled model of ordinary and mutated cells, we are inspired by [3] and by the new form of fast self-renewing process, [1], where a subpopulation of cells is considered to be always active in the proliferating phase.…”