TGFB1 and leukemia: Consistent with the mouse results, HSC transplantation in humans restored the protein expression levels of the above six niche factors (Figure 6c), and inflammatory factors, including IL‐1, IL‐6, TNF‐α, and TGF‐β, in the bone marrow were normalized in HSC‐transplanted leukemia patients (Figure 6d), together indicating the functional restoration of aged or declined niche by young donor HSCs in humans.