Foundations
From hematopoietic evidence to the first reprogramming concepts.
Dedicated timeline
Key stem cell discoveries in a consultable view.
Standalone timeline page with filters by level and source type, free text search, chronological sort and CSV export.
ScopeHistory, clinical steps, regulation
MethodMilestones tied to primary or institutional sources
UseFilter, search, sort, export
Journey
A visual path through laboratory work, clinical steps and regulation
Pluripotency
Embryonic cells, iPSCs and new experimental models.
Translation
Organoids, advanced therapies and selective clinical transfer.
Control
Approvals, regulatory warnings and interpretive limits.
Period
Navigate the field by year
1961
Foundations of the field
1961
1981
1998
2006
2015
2024
Active milestone
1961
basic
McCulloch and Till
Experimental basis for hematopoietic stem cells.
Rail
Visual selection of major milestonesMethod
How to read this timeline
Inclusion criteria
Entries are limited to milestones with recognizable historical relevance and support from a primary source, a professional historical source or an institutional/regulatory source.
Source types
`Peer-reviewed` refers to original scientific papers or indexed journal articles. `Institutional/regulatory` refers to sources such as Nobel Prize, EMA, FDA, ASH or equivalent official bodies.
What inclusion does not mean
Being present in the timeline does not imply broad clinical superiority. Some entries mark laboratory breakthroughs, others mark regulatory or narrowly defined clinical steps.
Scientific timeline
A more detailed sequence of major milestones
Original papers
Entries with `PMID` or `DOI` point to peer-reviewed primary literature or direct bibliographic identifiers.
Historical or institutional sources
Some milestones are anchored to ASH, Nobel Prize, EMA or FDA when the relevant point is historical recognition or regulatory status.
Interpretive limit
A historical milestone is not the same thing as broad clinical proof. That is why impact, limit and level remain separate in every card.
1961
Discovery: McCulloch and Till provide classic experimental evidence for hematopoietic stem cells in bone marrow.
Impact: they establish a modern experimental basis for stem cells in adult tissues.
Limit: the frame is still restricted to hematopoiesis, not general pluripotency.
Level: basic1962
Discovery: John B. Gurdon shows that nuclei from differentiated cells can be reprogrammed.
Impact: this becomes a conceptual foundation for modern cell reprogramming.
Limit: it is not yet an iPSC technology or a clinical platform.
Level: basic1968-1969
Clinical milestone: first successful allogeneic hematopoietic cell transplantation procedures are reported in severe immunodeficiency settings.
Impact: stem cell transplantation enters modern clinical medicine.
Limit: indications are specific and the procedure remains highly complex.
Level: clinical1981
Discovery: mouse embryonic stem cells are isolated.
Impact: pluripotency becomes experimentally tractable in developmental biology.
Limit: mouse biology does not yet solve human stem cell research.
Level: basic1998
Discovery: human embryonic stem cell lines are described from blastocysts.
Impact: human pluripotent cell research changes scale and ambition.
Limit: ethical debate and translational barriers become central immediately.
Level: basic2006
Discovery: Takahashi and Yamanaka generate induced pluripotent stem cells from mouse fibroblasts using defined factors.
Impact: reprogramming becomes a practical experimental paradigm.
Limit: still a mouse system, with major biological safety questions unresolved.
Level: basic2007
Discovery: human iPS cells are generated from adult fibroblasts.
Impact: disease modeling and human pluripotency research are profoundly reshaped.
Limit: genomic stability, manufacturing quality and clinical transfer remain open challenges.
Level: basic2009
Discovery: single Lgr5+ stem cells are shown to generate intestinal organoids in vitro.
Impact: disease modeling and tissue biology accelerate dramatically.
Limit: organoids are not whole organs and are not equivalent to routine therapy.
Level: translational2012
Recognition: Gurdon and Yamanaka receive the Nobel Prize for showing that mature cells can be reprogrammed to pluripotency.
Impact: the conceptual and experimental weight of reprogramming is globally consolidated.
Limit: scientific recognition does not erase translational barriers.
Level: institutional2015
Regulatory milestone: Holoclar becomes a landmark EU-regulated stem cell-based therapy in ophthalmology.
Impact: it shows that tightly defined stem cell therapies can cross into regulated clinical use.
Limit: this is a very specific product and indication, not a blanket validation of the field.
Level: regulatory2019-2021
Regulatory signal: regulators intensify warnings against unapproved regenerative medicine offerings marketed outside proper oversight.
Impact: public communication becomes a central tool against misleading commercialization.
Limit: warnings do not by themselves eliminate market overstatement or medical tourism.
Level: regulatory2024
Approval: FDA approves Ryoncil, the first mesenchymal stromal cell therapy for steroid-refractory acute GVHD in pediatric patients.
Impact: it shows continued forward movement, but only within tightly defined clinical and regulatory boundaries.
Limit: it does not justify broad claims about all mesenchymal or regenerative cell products.
Level: regulatory| Year | Discovery | Level | Impact | Limit | ID | Primary source |
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