TP53 and Pancytopenia: Since the loss of mTOR in hematopoiesis was sufficient to cause pancytopenia and impairment of HSC homeostasis [38] and P53 pathway was activated by DNA damage and played an important role in regulating HSC quiescence, self-renewal, and apoptosis, our results indicated that defects observed in Myh9-deficient mice might cause a perturbation of multiple genes and signaling pathways related to HSC maintenance.