Fig. 1.

Reduced frequency of haematopoietic stem cells (HSCs) and increased frequencies of multi‐potent lymphoid progenitors (MLPs) and common lymphoid progenitors (CLPs) in the bone marrow (BM) of young donors compared with older donors. Representative gating strategy for BM HSCs (CD34⁺CD38⁻CD90⁺CD45RA⁻), multi‐potent progenitors (MPPs) (CD34⁺CD38⁻CD90⁻CD45RA⁻), MLPs (CD34⁺CD38⁻CD45RA⁺), CLPs (CD34⁺CD38⁺CD7⁻CD10⁺CD45RA⁺), granulocyte–macrophage progenitors (GMPs) (CD34⁺CD38⁺CD7⁻CD10⁻CD45RA⁺), CMPs (CD34⁺CD38⁺CD7⁻CD10⁻CD135⁺CD45RA⁺) and MEPs (CD34⁺CD38⁺CD7⁻CD10⁻CD135⁻CD45RA⁻) from young, middle‐aged and old donors (a). Frequencies of BM CD34⁺ cells (b), HSCs (c), MPPs (d), lymphoid progenitors (e) and myeloid progenitors (f) among young, middle‐aged and old donors. Data are expressed as the mean ± standard error of the mean (s.e.m.). All P‐values < 0·05 were considered significant and are provided in the figure.