Table 2.

Oncogenic Risks for Methods of Pluripotency Induction in Somatic Cells

Method of Induction	Strengths	Weaknesses
Lentiviral vector	Robust reprogramming efficiency	Genomic integration, Reactivation of integrated transgenes
Adenoviral vector	Low risk for genomic integration	Low transduction efficiency, Limited transgene expression
Cre recombinase	Little genomic disruption	Low transduction efficiency, Integration of LoxP sites into host genome
PiggyBac transposition	Minimal risk for genomic disruption	Low transduction efficiency, Risk for uncontrolled rounds of excision-integration
Plasmid transduction	Minimal risk for genomic disruption	Very low transduction efficiency, Typically require use of oncogenes such as SV40LT antigen for successful induction of pluripotency
Minicircle	Minimal risk for genomic disruption	Low transduction efficiency
Sendai Virus	Minimal risk for genomic integration, relatively high transduction efficiency	Risk for continuous replication of viral vector in cytoplasm leading to improper silencing of pluripotency transgenes
Synthetic mRNA	No risk for genomic integration, ability to control transgene expression	Variable transduction efficiencies, High technical expertise required
Protein transduction	No risk for genomic integration, ability to control transgene expression	Very low transduction efficiency, Labor intensive
Small molecules	No risk for genomic integration	Variable off-target effects