Induced pluripotent stem cells, a giant leap for mankind therapeutic applications

Table 1 Some weak and strong points of induced pluripotent stem cells technology

Weak points		Strong points
Limitations	Possible solutions	Strengths	Further improvements
Slow, inefficient and variable reprogramming process	Banking of fully characterized iPSC	Easy reprogramming process to implement	Reduce time, and increase efficiency and consistency of reprogramming
Differential gene expression in comparison to ESC	Improve the reprogramming using other combinations of reprogramming factors	Strong proliferation capacity	Establish culture conditions promoting genome stability
Variable X inactivation status and genome instability	Test for X inactivation, sequencing to check for genome integrity	Allogenic and personalized cell therapy	Eliminate mutagenic potential and differential gene expression due to reprogramming
Point mutations	Whole genome sequencing to verify the absence of mutations - Possible correction by genome editing - Use cell source for reprogramming less susceptible to resist to mutations	Model human diseases, including cancer, and test patient-specific pharmacotherapies	Establish cells (tissues) with the adequate phenotypes characterizing the disease of interest
Immunotolerance of iPSC-derived cells	Preventive immunosuppression	May reverse cells aging	Understanding better the molecular mechanisms of partial reprogramming and aging markers
Differentiation protocols must be optimized to obtain iPSC-derived cells of interest	Many protocols have already been tested and published	Originate immune cells and use iPSC as vaccines to develop immunotherapies against cancer	Increase the variety of immune cells that can be reprogrammed
Potential tumorigenic hazard	Use differentiated and purified cells	Pluripotent cells	Prepare functional organs

iPSC: Induced pluripotent stem cells.