Shown in the top row are (wild-type) bone marrow cells (top) progressing from long-term self-renewal of HSCs to transient self-renewal of shortterm progenitors to fully differentiated cells. The rows below show the parallels between steady-state Ott KO hematopoiesis and normal aging, and the HSC exhaustion that occurs in Ott KO BM under stress, which is analogous to aged HSCs under stress.