Table 1: Comparison of the two most common types of Human Pluripotent Stem Cells (hPSC)-Pluripotent Human Embryonic Stem Cells (hESC) versus Human Induced Pluripotent Stem Cells (hiPSC).
| Type of hPSC | hESC | hiPSC |
| Derivation source | IVF leftover embryos | Adult tissues and cells |
| Derivation efficiency | Relatively high | Extremely low (< 0.1%) |
| Differ dependent on cell type of origin and derivation method, or reside in different developmental stages | No | Yes |
| Pluripotent | Yes | Yes |
| Expression of pluripotent markers, including Oct-4, SSEA-4, Tra-1-60, Tra-1-81, alkaline phosphatase | Yes | Yes |
| Teratoma formation in vivo | Yes | Yes |
| Prolonged normal stable self-renewal | Yes | No evidence |
| Open conformation of chromatin or pluripotent chromatin plasticity | Yes | No evidence |
| Chromatin acetylation and accessibility level | High | No evidence |
| Repressive chromatin remodeling factors, including Brm (Brahma), meh3 (histone H3 K9 methylation), SIRT1 (the class III NAD-dependent histone deacetylase), SUV39H1 HMT (the H3 K9 histone methyltransferase), or silenced chromatin | No or undetectable | Yes |
| Genetic imprints of adult cells | No | Yes |
| Abnormal gene expression or serious spontaneous mutations | No | Yes |
| Genomic abnormality and instability | No | Yes |
| Accelerated senescence | No | Yes |
| Immune-rejection | Low | High |
| RA induces neuroectodermal differentiation (efficiency) | Yes (100%) | No (0%) |
| NAM induces cardiomesodermal differentiation (efficiency) | Yes (100%) | No (0%) |
| Therapeutic or translational value | High | Low |
| Ethical issue and federal funding restriction | Yes | No |