2.

Progress on the generation of specialized cell types from hESCs

Germ layer	Cell Lineage/Tissue	Differentiation efficiency†	Chemically defined process‡	Surface markers for lineage purification §	References
Ectoderm	Keratinocyte	High	Defined	Not demonstrated	[46]
Corneal epithelium		Not defined			Serum/CM				Not demonstrated					[51]
Dopaminergic neurons		Moderate			KSR				Not demonstrated					[55, 56]
Motor neuron		Low			KSR				Not demonstrated					[58]
Oligodendrocyte		High			KSR				Not demonstrated					[60, 61]
Mesoderm	Osteoblasts	Not defined	Serum/feeders	Mesenchymal precursors (CD73)	[80, 81]
Chondrocytes		Not defined			KSR				Mesenchymal precursors (CD73)					[80, 85]
Cardiomyocytes		Low			Serum/feeders				Not demonstrated					[69, 73, 75, 79]
Haematopoietic cells		Moderate			Serum/feeders				Various available					[91–93]
Endothelial cells		Moderate			Serum/feeders				Various used					[91, 92, 96, 97]
Endoderm	β-islets	Moderate	Defined	Definitive endoderm only (CXCR4)	[113]
Hepatocytes		Not defined			Yes				Not demonstrated					[117, 118]

^†Efficiency is reported as the percentage of cells staining positive for a lineage specific marker. High denotes > 90%, moderate denotes < 90% and > 30%, and low denotes < 30%.

^‡Chemically defined processes use serum-free medium in the absence of feeder layers for all differentiation steps.

Conditioned medium, CM; knockout serum replacer, KSR

^§Surface markers available for live cell sorting (i.e. magnetic or fluorescence based).