Multilayered control of retinal stem/progenitor cell fate in the single-cell and organoid era: Developmental blueprints and regenerative opportunities

Table 4 “Minimal controllable node set” as an operational scaffold for more reproducible, mechanism-anchored fate engineering - modules, targets, tools, and success metrics

Module	Engineering objective	Representative control nodes mentioned	Implementable tools (examples you already cite)	Timing logic	Primary success metrics	Typical failure modes
TF intent	Specify lineage/subtype + maturation	Combinatorial TF designs; staged programming	AAV timed expression; programmable delivery platforms	Competence induction → commitment → maturation	Fate fraction + subtype markers + functional readiness	Single-factor insufficiency; wrong temporal window
Epigenetic permission	Open required enhancer repertoire	Enhancer priming; cis-regulatory logic; 3D genome nodes	dCas9-based recruitment/CRISPRi; enhancer-first interventions	Must precede/overlap TF pulses	ATAC congruence; motif availability; reference-mapped maturity	Global de-repression; non-specific dedifferentiation
Microenvironment calibration	Prevent reversion; support integration	NF-κB; monocyte infiltration (CCR2+); metabolic/ECM/oxygen tuning	Immune phase control; niche editing; metabolic conditioning	Permissive inflammation early → resolution late	Stability over time; reduced gliosis; integration-level readouts	Reactive reversion; inflammatory bottleneck; stress collapse

TF: Transcription factor; AAV: Adeno-associated virus; 3D: Three-dimensional; dCas9: Catalytically dead Cas9; CRISPRi: CRISPR interference; ATAC: Assay for transposase-accessible chromatin; NF-κB: Nuclear factor kappa B; CCR2+: C-C chemokine receptor type 2-positive; ECM: Extracellular matrix.