Bone Marrow Cell Atlas Created for Improved Leukemia Research

Why It Matters

An age‑matched healthy baseline enables researchers to distinguish leukemia‑specific alterations from normal developmental changes, improving diagnostic precision and drug targeting in pediatric oncology. This shifts the field away from reliance on adult data toward pediatric‑focused precision medicine.

Key Takeaways

• 91,000 pediatric bone marrow cells profiled across nine donors.
• Children's marrow shows distinct cell types and proportions versus adults.
• B‑cell production dominates under ten; older shift to myeloid/T.
• Atlas combines RNA, protein, spatial data; freely accessible worldwide.
• Enables age‑matched comparisons to pinpoint leukemia‑specific changes.

Pulse Analysis

The emergence of single‑cell multiomic atlases has transformed how researchers dissect complex tissues, yet pediatric bone marrow has remained a blind spot. By leveraging high‑throughput single‑cell RNA sequencing, surface‑protein profiling, and spatial transcriptomics, the Princess Máxima Center has filled this gap with a comprehensive reference of nearly 91,000 cells from children aged two to early adulthood. Making the dataset openly available aligns with the growing open‑science movement and provides a standardized baseline that can be integrated into bioinformatic pipelines worldwide, accelerating discovery across hematology and immunology.

Analysis of the atlas uncovers striking age‑dependent shifts in hematopoietic output. In children under ten, the marrow niche prioritizes B‑cell lineage commitment, whereas adolescents and young adults display a tilt toward myeloid and T‑cell production, reflecting maturation of the stromal microenvironment. Moreover, the proportion of hematopoietic stem and progenitor cells versus mesenchymal stromal cells changes markedly with age, suggesting that stromal signaling drives lineage decisions. These insights challenge the practice of borrowing adult reference data for pediatric studies and underscore the necessity of age‑matched controls when interpreting leukemic aberrations.

For clinicians and drug developers, the atlas offers a practical tool to differentiate disease‑driven transcriptional signatures from normal developmental variation, sharpening the search for therapeutic targets in childhood leukemia. By mapping the spatial architecture of the marrow, researchers can now explore niche‑specific interactions that may influence treatment resistance or relapse. The resource also sets a precedent for similar pediatric atlases in other organ systems, fostering a more precise, age‑aware approach to precision medicine. As the community builds upon this foundation, we can expect faster validation of biomarkers and more tailored interventions for young patients.

Bone marrow cell atlas created for improved leukemia research

By Princess Máxima Center for Pediatric Oncology · edited by Gaby Clark, reviewed by Robert Egan · February 18, 2026

Multimodal single‑cell reference map of healthy pediatric bone marrow. Credit: Nature Immunology (2026). DOI: 10.1038/s41590‑026‑02422‑9

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The GIST

What do healthy bone marrow cells in children look like? For the first time, researchers have mapped this out. Scientists at the Princess Máxima Center examined nearly 91,000 individual bone marrow cells from healthy children. Their findings show that children's bone marrow is clearly structured differently from that of adults. The researchers compiled the data into an overview, an atlas, so that other researchers can also use it.

Bone marrow is found in the centre of your bones. It produces blood cells such as red blood cells and white blood cells. In leukemia and other blood disorders, this process goes wrong; diseased cells develop instead of healthy ones.

Researchers study bone marrow to understand exactly what is going wrong and how children with leukemia or other blood diseases can best be cured. Comparing bone marrow cells from healthy and sick children is helpful in this process. But until now, such data did not exist. Researchers therefore relied on bone marrow data from adults.

Children's bone marrow is different

Researchers at the Máxima have now shown that children's bone marrow works differently and consists of different types of cells, in different proportions. The data have been compiled into an overview, an atlas that is now freely available to researchers worldwide. In this way, this study helps further improve treatments for childhood leukemia and other blood disorders.

This research project, conducted by the Belderbos group and the Single Cell Genomics Facility, was made possible in part by the Landsteiner Foundation for Blood Transfusion Research and the European Research Council. The Single Cell Genomics Facility is supported by KiKa (Children Cancer Free Foundation).

Nearly 91,000 cells

The bone marrow cell atlas consists of nearly 91,000 individual bone marrow cells. These cells come from nine donors aged between two and 32 years, covering multiple developmental stages. More than 20,000 of these are hematopoietic stem and progenitor cells and mesenchymal stromal cells. For all cells, both the mRNA expression profile and the surface protein expression were recorded using single‑cell technologies. The “architecture” of the bone marrow was also examined using spatial transcriptomics techniques.

Changes in blood cell formation

Analysis of the data reveals clear age‑dependent changes in hematopoiesis, the process of blood cell formation. In children under ten, the bone marrow is primarily focused on producing B cells. In teenagers and young adults, the emphasis shifts more toward myeloid and T‑cell production. In parallel, the bone marrow niche—the cellular and molecular composition of the microenvironment that supports blood formation—evolves with age.

The results of this study are published in Nature Immunology.

Postdoctoral researcher Dr Evelyn Hanemaaijer, Ph.D. candidate Konradin Müskens, and bioinformatician Ireen Kal share first authorship and carried out the research in the Belderbos group, in close collaboration with the Single Cell Genomics Facility at the Máxima Center.

Age‑ or cancer‑related differences

Dr Mirjam Belderbos, pediatric oncologist and research group leader, led the study together with Dr Thanasis Margaritis, Single Cell Genomics facility lead. Belderbos explains, “That bone marrow and bone marrow cells differ strongly depending on age is highly relevant. It shows that comparing cells from sick and healthy children within the same age range is crucial to distinguish cancer‑associated changes from normal age‑related differences.”

Margaritis adds, “An increasing amount of research is carried out at the single‑cell level. The insights gained through this work and the atlas will help us, and many others, to further advance research into the development and treatment of childhood leukemias and other blood‑related diseases.”

Publication details

Evelyn S. Hanemaaijer et al., Single‑cell multiomic atlas of healthy pediatric bone marrow reveals age‑dependent differences in lineage differentiation driven by stromal signaling, Nature Immunology (2026). DOI: 10.1038/s41590‑026‑02422‑9

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Key medical concepts: Leukemia, Hematopoiesis, Stromal Cell (Mesenchymal), Spatial Transcriptomics

Clinical categories: Oncology, Pediatrics, Children’s health, Laboratory medicine